Proper? ....look into either Wolfe Racecraft, TRZ, or UPR's rear drag suspension package. Other than that, a quality set of adj. shocks will take care of the rear. A tubular K-member, A-arms, and coil-overs will get you pointed in the right direction for the front.
The NMRA SSO cars are limited to 28x10.5 slicks... they typically run in the high 7 - low 8 sec. range w/ a ladder bar suspension.
With an efficient, stock-type suspension, you can dip into the mid 8's. FFW Renegade cars are doing it...
Looks to me like you can put down well over 1000HP+ with those little tires.
....just depends on how crazy you are. The 28x10.5 Outlaw cars tend to get out of shape on the big end, sometimes.
FWIW, NMRA Real Street cars make great power and put it down with 26x10's ....they just recently entered the 9 sec. realm, going 9.90's (and one 9.7x pass that I know of).