Going with the kits is certainly the easiest way to start out, you get to skip the harder aspects and jump straight to making it look pretty. Pretty fun to boot. As far as where to buy goes, check out
http://usaknifemaker.com. They're my personal favorite knifemakers supply place, the prices do tend to be a little higher than average, but the selection it good and the website is actually well designed and informative of all the products, a rarity for knife supply houses for some reason.
It should also be said that finding a complete kit for a fixed blade knife is a bit of a rarity. Usually you'll but the knife blade, then whatever handle scale material and pins and do the fit-up for those yourself. Nothing complicated, just cutting to shape, but not quite as simple as screwing everything together. Still a fun project though.
If you've never made a blade before, I'd go for a simple, full-tang blank like this:
http://usaknifemaker.com/knife-blade...40c-steel.html
And whatever color of G10 tickles your dance for the handle material. I'd go with g10 over wood because for my money the g10 is actually easier to work with. Not that wood is hard by any means, but the finishing aspects can get confusing, especially if you've not done much woodworking. G10 you just file/grind to shape, sand to 220 and you're good