Spool all the way. Cheap, simple, strong, & effective. Totally streetable. You're not building a corner-carver or something you're going to take out on a road course. For a street/strip car, a spool is the only thing I would consider using. The one thing you want to make sure you check when using a spool is tire circumference (you should check this anyway). A lot of tires vary quite a bit in circumference. If one rear tire is taller than the other, two things are going to happen when you're using a spool:
1) The taller tire is going to wear very rapidly.
2) The taller tire is going to push the car towards the right or the left depending on which side it's on. It may not even be noticeable under normal low-speed driving conditions, but can cause serious problems under power, especially at the track or on a really well-prepped street where the car hooks.