Depends on what you want in a kit. If you want to build a collector-grade weapon you can get an STG-58 kit (prices have been seen as high as $600) then add the US parts and put it on a DSA receiver. Total cost, about $1000, kinda pricey, at that price it's better to just buy one from DSA.
Or, if you just want a nice working rifle that you can still put together on a budget, you can get an Imbel kit from
www.gunthings.com/ for $259, US parts, and then an Imbel upper. Dealer's Warehouse
www.tdwsales.com was supposed to be getting a new shipment in. I think they're around $225 or so. What I used on mine was a US H/T/S, Penguin bargain stock set, and US gas piston. You have a few options, but the US parts are a bit pricey since you have 7 to put on a rifle w/muzzle device. I've since changed the barrel out on my Imbel to a Para barrel and put on a DSA para lower, and I think it's an AWESOME setup for a .308 rifle. But, even the full-length barrel w/fixed stock is a really nice handling battle rifle.
The marketplace at falfiles is a great source for parts, receivers, in general all you need to build. There are TONS of folks in OH that have built them, if you don't have the tools then I'm sure that someone near you does, and like AK builders they're always happy to help. It's really a simple rifle to put together in the garage, all things considered, and the only tools you need are a barrel vise and receiver wrench for upper assembly and a press to get the locking shoulder in and out. A lot of these Imbel kits were carried but not shot, so the finish is bad but the internals are very nice.
Hope this helps.