My Opinion
Much prefer a right-sized AC pump than a DC pump, IMO.
Done right, you don't even need a valve. Plus, AC pumps should last longer. (There's no track record for DC pumps yet...I see no reason to assume a cheap DC pump will outlast a QuietOne, Mag or Eheim which all have amazing long-term track records.)
My Recommendation
The three top choices I'd recommend....QuietOne, Mag or Eheim. Though there are definitely other good pumps out there too.
Eheim doesn't offer as many size choices in their most-esteemed Universal Hobby Pump line, but if you have the budget, this is still the rolls royce of pumps.
The QuietOne and Mag both make really sensible alternatives for a lot less money. The Mag is a stronger pump (and higher wattage) but still very quiet. The QuietOne is still pretty strong, but I think it is actually quieter than the Mags. I have at least one of all three pumps, FYI.
Sizing
Sizing the pump is about the actual throughput you need - not the rating on the pump.
If you are doing anything beyond a basic plumbing job, you should try to find and use a head-loss calculator to account for the extra height, twists and turns.
A basic plumbing job can be estimated well enough from the flow curves published by the manufacturers.
We'll assume your 75 is 4' off the ground.
75 gallons of display needs between (75 x 2 =) 150 GPH and (75 x 4 =) 300 GPH of return flow. That's it.
If you want to account for "wear and tear and buildup in the plumbing", maybe you'd go for as much as (75 x 5 =) 450 GPH.
More than that doesn't really do anything for you and can actually cause problems like noise, splashing, micro-bubbles, etc.
QuietOne
According to
Lifegard Aquatics, a model 2200 (rated at 600 GPH) would do the trick and give you around 400 GPH. Way more than enough and only $58. A model 3000 would really be overkill IMO. I like that these pumps have built-in, male 1" threaded outlets.
Mag
According to Danner's info on the Mag pumps
posted here, anything from a Mag 3 (rated at 300 GPH) up to a Mag 7 (rated at 700 GPH) would do the trick - even if your return was up to 7' high. If I'm literally right in my guess at your tank being 4' high and you have very minimal plumbing, a Mag 2 could even pull this off. That's a range between $62 and $90 online....I'd even pay a small premium to that if anyone is still selling those local to you. These pumps really are tanks. The only reason not to consider these is if you're (still) running halide or T5HO lighting and have a tank with heat issues. I like that they have built-in, 1/2" male threaded connections on the IN and OUT.
The QuietOne at 45 watts is more power efficient than the Mag 7 at 60 watts for similar performance. However if you select one of the smaller Mag's I mentioned, power usage can go as low as 20 watts(@$62).
Eheim
Eheim's 1260 would appear to be in the same size class as the 2200 and Mag 7.
Rated at 600 GPH, expected to deliver around 400 GPH at 4'. $169.
Definitely worth it, but not the only pump worth considering.
This has a 1" female threaded IN and oddball 5/8" threaded OUT along with an assortment of barb fittings. I have a littler 1250 and I had to jump through some hoops to get its 3/8" outlet plumbed to my skimmer at the time. The skimmer was also 3/8" but it's an odd size part to find. I bet 5/8" parts aren't for sale everywhere either.
Personally, I think I'd go with the Mag 5 or 7 or QuietOne 2200. But heat is not a consideration for me. Budget and reliability are.
