You should have a lot of fun with your Fuji. I have the GA645Zi and that zoom lens is superb (also the warning when the lens cap is still on can be handy, ahem!). I can never get over how light these 645 cameras are - perfect for people travelling - and of course, they can take 220 film as well as the usual 120.
By the way, I bought a replacement lens hood for my Fuji last week from keh.com and I noticed that they had lens caps for other Fuji 645 models in stock - might be worth checking out as they were not very expensive.
I also managed to get hold of the Fuji GA Strobe which is a useful and reasonably powerful dedicated flash and increases the utility of these cameras. I've just spotted a couple of the GA flash brackets on ebay too. The only problem with the GA645Zi - the price keeps nudging north and that seems to hold good for most the Fuji 645 range.
Enjoy your camera - the GA645i is a gem.