Not much digital experience yet, but alot of film and other areas. On the question of buying a body, vs lense vs wait for the trip: I've always believed that the best investment for most people is in the lens over the body. That's where you get the most bang for the buck, and the best performance. Especially if you might be moving to or adding a FF sensor body, I'd look into EF lenses vs EF-S because you can use that lense on either where EF-S does not work on FF cameras. IMO it's better to be able to swap them when desired otherwise you'll be buying lenses for both formats.
On refurbished bodys, that all depends on who did it and how good they were. I've bought a number of refurbished items in the past, usually when it's refurbished it's gone through by hand while the original build may have been done by machine. A human may detect something a machine wouldn't. Overall, I've had good lucks with refurbs and I can't say I've had a worse failure rate than non-refurbs.
My 2 cents.
