The problem here is that you get into the "While-I'm-At-It" syndrome - something I'm intamitly familer with. While I'm at it, might as well do rings and bearings. Cam. Lifters.
Oil pump. pistons. Crank. etc. Before you know it, you'd have saved time and money by simply installing a new or rebuilt short block from your favorite rebuilder.
You're not really asking much - a simple inexpensive and fun street machine. Your stock engine probably makes around 200-220 hp. Adding another 100 to that with a rebuilt engine is pretty easy, reliable, and inexpensive.
There are lots of short and long blocks available that will do exactly what you're looking for. Ford is a good source for a long block, as you can get them locally for a good price, and they have a warrenty. Pretty hard to beat that. Their cheapest long block makes 340hp, and has a very flat torque curve - $4,000 USD.
Ford Racing Performance Parts