What cam to use.

Seeing how you want to use a blower later on, it would be a chocie of cam for fast now and change later or cam for later even though you do not have a chareger on the car now.

I think a custom cam would do it well.
The amount of clearance you have can be found out by putting clay on top of the piston and start turning it over by hand.
This is the only way to find out because even if someone else has the exact cam you have now, theres could very well show different clearances.