Purple Cam Design Question

tooslow - Stick with the solid flat tappet deal, consult the cam manufacturer for proper spring and break in procedures, run a good high zddp oil like Joe Gibbs, Brad Penn, or the Not Legal for Street Use VR-1, and you'll be fine.
The MP .528 is a nice small cam. If you want more pep with the new heads, I'd go with something like the XS282S or the Magnum 294S both from Comp.