Shaun, not having finished mine yet etc, you will end up spending loads of money to not really go that quick.
I frequently have thoughts about throwing in the 4age for the 13bt import motor, around the same money in the end
a little more work but it would be a whole different league from a 4age, as i said ive had a series 4 rx7 with a hi flow more
boost etc and it was an absolute weapon, now imagine it in a car thats a few hundred kg's lighter!
But, if you want to go the 4age, i have a computer and injectors here you can buy from me cheap they are just spare.