Sell it and get an 86 or S13
I'd say new pistons while you are in there, lightened flywheel and a good clutch and you should be all done. I/H/E don't really add all that much, but on a VTEC motor they do add a little. You'll want to replace the throttle body and intake manifold too, possibly, which would be more beneficial than the intake is. I dynoed a foam filter in the stock air box and that gave +2 HP alone, but with the full Comptech intake, it didn't really make a huge difference, just gave me better throttle response.
What about SUSPENSION? Suspension is what makes my DA fun to drive.
I loved my 91 Si (red). It was an excellent car that was very fun to drive. I was sad when I sold it, but extremely happy that I bought a GSR to replace it
True old school guys don't refer to the VTEC head swap as Mini Me, we call it Frankenstein