PG-150A is the model of the pump. A -0 might barely work (very small main pill) or a -1/2. Optimal would be a -1 sized pump. Look at the serial number stamped into the pump body. If it's one of the small sizes, we can put bigger guts in it. Or he might want to look around for a -1.
On heads and cam...the answer is "how fast does he want to go" and "how much does he want to spend"?
The better the heads, the more power.
Spud