I have never ever seen a kenne bell adaptor intake to put one on a 96-98 4v. this is because the heads are different. The heads are called B heads. the 99-up 4v heads are called C heads. the B heads have 8 intake runners per head whereas the C heads have 4 intake runners per head. The intake is different, so you cant use a 99-up twin screw intake on the B heads. You're better off buying a Cenrifugal SC and an MMR Intake.
KB makes a kit specifically for the 96-98's. The older kits used a smaller 1.7 blower, and the newer ones are 2.1L. They are an ok blower, but not very efficient due to them not having an intercooler option like the 99-04 kits.
The top option in the twinscrew game would be to basically duplicate an 03 cobra set up with a set of 03-05 heads (or atleast 99/01's), complete eaton swap (minus the eaton), and get an 03-04 specific twin screw ........EXPENSIVE!
The 2.1, with a post blower methonol kit can also some serious power.
For simplicity, its hard to beat a properly set up centri 4v. Dont go too low on the compression (I never suggest less then 9.5:1 on a street driven centri 4.6). My next centri build will be 10:1
Dont wast your time with a p1sc. Jump right to a d1sc, and if you plan on making over 700 eventually, think about getting an f1
If you like vortech, the S trim will make pretty good power, and do a little better then a p1sc when spun hard, but a T trim is a nice starting point for a be head 4v with a built bottom end. Jump to the YSi if you want more then 700.