Power head on the right is a Maxi Jet by Aquarium systems.
Actually quite a good power head.
Also looks like an Eden power head in the middle with moving nozel for wave making, not so crash hot as the mechanism clogs up (well dod for me)
Pump in the left looks like a Rio, has a reputation for blowing up.
The overflow looks to be a Tunze box.
http://www.tunze.com/149.html?&L=1&C=AU ... zeprod_pi1[predid]=-infoxunter005
Looks to me as you do need a bid return pump, the power heads probably are not grunty enough although the RIO maybe.
Actually, looking at the pipe work the original owner may had both the RIO and Maxi-Jet as return pumps. Hard to know without knowing the flows rates and head pressure.
Personally I like the Eheim 1060 (think their now called 1260) pump for return, super reliable and easy to get a 2nd hand one off a marine guy.
If your wanting to clean the gear off, soak it in a solution of water and white vinegar over night. Will clean it off like new.
The plumbing Fittings (black ones) are Hassens and widely used for plumbing on fish tanks here
http://www.hansenproducts.co.nz/
Hard to comment on the sump with put seeing the whole item and how itsd baffled. Marine sumps do tend to be a bit more customised the a freshwater sump. There's a sump set up on TradeMe at the moment that maybe more suitable (No, it's not me but worth a look at)
Oh yeah, I'm on holday with a ton of time to kill :bounce: