I think you're asking for very practical advice. Many here are hobbyists with a strong drive to buy the latest greatest gadget
If photography is not a serious hobby and this trip is more important as a holiday with your important other half, then just get the latest prosumer camera by reading the camera reviews. Likely easy to use, easy to view for checking, and long lasting batteries would be important for holidays.
Check out camera review websites like
http://www.dpreview.com/reviews/specs.asp
Or better still, visit a reliable camera shop and ask for recommendations, and to touch and feel the camera if they allow.
If you had not much time to "play" with 350D, then likely getting another DSLR will become white elephant after the holiday. For second hand, I guess the Nikon D70s might be good bargain now because the new D80 was launched recently. For convenience, just get the kit zoom lens that comes with the camera body. Also, carrying a "big" DSLR around is sometimes not much fun and may attract unwanted attention.
Or, why not borrow a DSLR from friends/relatives, etc? You can always try first before deciding to invest