So sick of the V8 or die guys...
Been down that same road before, 5K for a used "insert name of some non-descript pos" or 5k for a decent a-body with a /6. 5 years from now, the slant valiant will be worth more than that corolla / accord / civic, and the slant wont cost a fortune to fix or keep running.
I have about 6-7k into my Duster including purchase price and all of the upgrades. Take your time, come up with a plan ( and stick to it ) and build as time/money permits.
After having driven a 4-speed turbo slant for the last 18 months I have to say that it behaved very well under boost, would boil the 245's on the rear, had mild manors when not in boost, AND the looks on peoples faces were priceless.