5d or xti and IS lens, hard decision, long post

ok this is for all you other canon owners on here, i hesitated to post this because similar threads on other forums always sort of go inconclusive into "you have to figure out your shooting style first", well as everyone can see from the many posts i sort of shoot all kinds of things
given parameters
1. i'm going to have a crop sensor body as long as they are still made, i like having the extra tele range for spring/summer when i do a lot of shore bird stuff, that's when the big boy(500 f4 IS) comes out of the case
2. i have a lot of late teen/twentysomething neices and nephews, who seem to be getting married at the rate of 1 a year, and they all come straight to me to make sure i'll have my camera at the wedding, not to shadow or take the place of the pro, but because i usually know the intimate family relationships, i always seem to get that one of grandma or dad with the joy on their face, i haven't told them it's more a case of being in the right place at the right time then skill!
we are going on the disney magic next may, inaugural med cruise, preceded by 3-4 days in barcelona, much city/street/park/building shooting anticipated,
security of gear is an issue, like it or not, many european cities have high levels of petty street/pickpocket theives, i am waiting for a mec sling pod bag to arrive so i can check out the capacity, it's necessary to keep your gear secure at all times and it's a good idea to wear it across the front, NEVER EVER A BACKPACK OR FANNY PACK, too easy to open unoticed from behind
i've decided to sell a couple of lenses that i rarely or never use anymore, i will have enough funding to go one of 2 ways
1. buy 5d, i have 17-40 f4L, i can take 28-70 2.8 L or tamron 28-75 f2.8 if iq is good enough for my tastes(much lighter), i would need to get a 50mmf1.4 or rent for available light inside shots, many churches and museums if allow photos at all, no tripods or flash
2. buy ef-s 17-55mm f2.8 IS, and take either 20d or buy rebel xti if sling pod requires smaller dslr, this lens gets many top reviews and with IS may allow available light shots without taking a prime along(advantage 1 less lens to carry)
$ situation allows one path or other, weight and size are considerations here, i do have a neice marraige in oct, ff would be nice but not necessary, i do see myself going ff eventually, rumors in the wind have 5d upgrading after pmia in march, but time frame may not allow production, shipping in time for me to learn the gear before the trip,xti available now for learning curve
70-200 f4L may or may not make the trip, 70-300 f4.5-5.6 IS did well on safari at mf and may be rented if room in pod
sorry for the long post but i wanted to give as much data as possible for informed opinions
thanks for any input
lenses being sold to finance this
canon 100-400 f4.5-5.6L IS, used once in last 2 years, replaced by full range of f2.8 and f4 primes
canon 80-200 f2.8L, too honking heavy, replaced by 70-200 f4L
sigma 15-30mm f3.5-4.5, replaced by 17-40 and 10-22 ef-s
gary

 

decided to go with 17-55 and an xti body, mostly for reasons of security and transportation, my mec sling pod arrived and i can comfortably take xti with 2 lenses, 3 if i fit them in carefully, 2 if i take the 20d or upgrade to ff.
i've also decided after reading a few reviews to let the full frame technology mature a little more before making the jump, 2 main reasons.
1. before i commit that kind of money to a camera i want to see a few more things added, a dedicated mirror lockup button or ability to make an existing button function as mirror lockup, a faster flash sync, at least 1/250, iso in the viewfinder, maybe an auto iso ala nikon
2. some of the canon L lenses need some updating, if a lens has faults, full frame will make them apparent, and some of the current L grades need some work, forget using consumer grades on ff, those lenses from what i can research have real serious flaws showing up
i'm sure i'll be able to get some acceptable shots in europe with an xti, i'll be buying by 2/7 so i'll have plenty of time to read the manual and learn the controls before the trip
trip kit shaping up to be 10-22, 17-55 IS, and maybe 70-300 IS, or 28mm f1.8, this should be lightweight, cover my needed focal lengths and be inconspicuous enough not to attract a lot of street theif attention
and as always remember the t-mip code
F8 AND BE THERE

 

this is rebel xti (400d) in stockholm. The senor cleaning feature is worth the price of admission. I hate loading up 20d images and seeing black smudges on otherwise great photos. so the 400d will do great in europe if you have good glass. (these were made with the 18-55 kit lens - i had to buy the camera in sweden and tax is 25% so i had to get the add on lens).

in my trips to europe i found a decent walk around zoom or couple of primes solves all problems. I try to go light and try to be unnoticable. (i originally went to sweden with a rangefinder but work forced me to have to buy a digital slr). but a 28-135 type of zoom plus a 50/1.8 or so plus a 135mm+ tele lens should solve all issues. your kit sounds good if the 17-55 solves the low light issue (catholic-mediterrean churches beg to be photographed but no flash is allowed). it might be wise just to through in the 50/1.8 if you have it but then again. the lighter the better when traveling.

the 10-22 should do well on the boat since cabins and halls are so tight.

 

top photo is the Vasa ship museum, very dark hard to hand hold with a slow lens. the second is the kongholmen bridge to marieberg at sunrise (about 9 am in january) thats the soderholmen church on the right.