Note that there are a bunch of ways to do this. HDK (HemiDenny above) has a nice coil over front suspension that should get the motor mounted and an 8HP in the car without cutting the floor. But it adds cost upfront. There are many debates about the pluses and minuses about the COC vs torsion bars, not going there. Only pointing it out as an option in case you weren't aware. I will say I don't think a COC and rack and pinion is the only path, but I can't argue that there are advantages, one being that you very well could get the 8HP without the work of building a floor.
In the end it really comes down to what you want and what you are willing to invest to get there. Not everyone wants the same thing and you need to be clear about what you want going into it. Otherwise it can turn into a black hole that sucks you dry.