Well, got my stuff today, and here is the datasheet for the Fairchild FDS6690A FET that the Novak SPY uses:
http://www.fulcrum.ru/Read/CDROMs/FA...l/FDS6690A.pdf
It looks like the IRF7455 would be a nice replacement, handling 15A, and having an "on" resistance that is half of that of the Fairchild part.
You would need four chips to do the job, at a cost of a little more than $6 and shipping.
BTW, nice of Novak to use those transparent cases. Saves me from having to disassemble the product to reverse-engineer it... :lol: