Is this a good engine for the price

Check out the Magnum builds on this site. A 5.9 with a mild build will easily go 375 to 400 hp and use your tranny ,driveshaft, etc. The big block idea is great, but it would be cheaper overall up to about 500 hp to stay small block. After that, a big block will start to make more sense, mainly for drivability. Another thing to consider is weight distribution for street traction. The lighter you can keep the front end, the better off you are. I doesn't pay to have 600 hp and get stomped by a guy that only runs 500 hp but can stick the tires and go! If I were going to build a street lite bandit, with your car body, It would get aluminum heads, on a smallblock, battery in the trunk, engine carefully set back as far as you can massage the parts that hold it in, rear axle forward as far as you can get it with the clearance you have, and a great suspension set up for max rise on takeoff.
Being able to do some fab work in my shop, I would also drop the stock fuel tank, cut the wheel well out of the trunk area and mount a flat gas tank further back! Look in the Hot Rodder adds, for gas tanks that might sit in there just right, level with the trunk floor. OK, a little off topic, but you wanted to kick so Furd butt!