Advice: Solid Roller or Hydraulic Roller for street car
3.55 gears* and a converter will be the best bang for the buck on the current set up. it would be a totally different car.
i'd do that first. might find that's just what you were looking for.
but if not, that stuff will compliment any future endeavors motor wise.
anyway, you're not running mid 11's with bolting on a set of heads and throwing a cam at it. you're going to have to build a bottom end with some compression to get there-- hence everybody saying to ditch the teen and boogie down with a magnum.
you seem set on the roller cam, and far be it from me to tell somebody else how to spend their money. but if you're going that route, then pivoting to a magnum will help absorb a lot of associated costs in that it's already a roller motor and the valve train is set up for it.
personally, i'd do the gears and converter so that i can run around and enjoy the car while building a motor on the side.
*3.90 gears would be okay too, it's not like you're commuting in it.