I second Alan's opinion. I have the 580EX and a 420EX. The 580EX is awesome. I use it at church and can light up the stage from 60 feet away. The 420EX is OK for up close stuff, although I only use it as second fill flash (slaved off the 580EX). The 430EX would work fine for taking portraits and other pictures that are not too far away.
I own a Bogen Manfrotto tripod and really like it, although I did not get one of the real light ones (3021B w/488RC2 HEAD).
As for whether to get a flash or tripod first, it depends on what you primarily shoot. If you take a lot of portraits and can shoot at shutter speeds that will let you hand hold the camera and get a sharp image, then I would get the flash first. I rarely use my tripod. My flash is always on my camera, since I take a lot of candid photos. If you like to shoot with long shutter times, then the tripod is a must.
You could get a good flash, then buy a used or relatively inexpensive tripod. Just make sure the tripod is rated for the weight of the camera and attached gear.
Thanks Allan! I guess I may be going with the flash first then because it seems I'll be doing a lot of portraits for side jobs. I guess it would only make sense to start with the flash and then get the tripod later down the road.
I was looking at the tripods again on Adorama and B&H and man there are so many! I even limited it to Bogen/Manfrotto and there was still a bunch of stuff. I guess I just have to filter through it, haha.