I've got a G5 that's modified to run both pumps recirculating...it's a little rough looking frnkly. I was just going to keep it if I ever decided to use it since it works perfectly (one impellar/magnet is like 1 month of use) and I couldn't care less about how it looks.
I'd probably mod it again to run one pump recirc. one flow through (to feed it and omit the addition of a feed pump).
PM me if you're interested.