I fitted a Huco low pressure electric pump. I think it's rated at 2.1psi works a treat. I made an adaptor plate from some 3mm galv sheet that blanks off the original pump aperture in the block and has two additional hole that I put two small cotton reel mounts. The Huco bolts onto these cotton reels. This partly isolates the pump from heat and vibration, we'll in my mind it does!
I see Peter's beaten me, but I typed more words!
Iain