SR I would say 3.4 GPM since mine is a pro blaster. There is an extreme pro blaster which is 5.5 GPM.
I found a pro blaster like mine on eBay but its just the pump:
http://cgi.ebay.com/ebaymotors/SHURF...spagenameZWD1V
Oh wait, here is a complete washdown system and its cheaper than the pump alone!:
http://cgi.ebay.com/ebaymotors/SHURF...spagenameZWDVW
Hope this helps. I think around $130 is about what price you'd pay at West Marine if my memory serves me correctly.
Blue