Russ,
What put you off using a Zeta along with a porty?
Personnaly I think this kind of arrangment is the future. Plenty of heat from a diesel burner, = nice low running costs'.
More than enough pressure from the pump, would get it running off the domestic AC supply rather than a small donkey engine, again low running cost's.
Not so sure about the extractor in this case, but a decent porty with auto pump out will sort out the suction side of things, again easy to maintain and cheap to run.
Forget about those long, time consuming hose runs. Just take the porty to where ever its required.
Daren