I like my Thresher Tank fitted in a commercial milk crate from Jersey.
It holds rods, game clip, bait net, gaff, knife, a lipper, and more if you want.
I run it on a 6 volt 12 amp battery, and at 4.7 gallons its plenty big enough, verses Hobie's 8 gallons.
The entire set-up, tank, battery, crate, rod holders, and bilge pump, weighs 19 lbs. without water.
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You could probably use the T-Tank with a bilge pump that mounts inside, or outside of the tank itself, then run a piece of 3/4" hose through a scupper hole for reduced drag.
I believe Tanks are sold both with, and without pump gear so you can custom build to your own needs.
Lots of accessories to build a good tank are available at the BWE online store.
Heres a pic of my set up:

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Ron Lane, of Fastlane Sailing had a homemade tank set up the way you described how you would like Your to work.
ie. not dragging the pump.
I can only find 1 pic of his tank on my computer.
As I remember, the pump was located inside of the tank, and both the intake, and discharge hoses went through both rear scuppers.
L. Lauman had a similar set up on his Adventure.
I would bet Ron still has this tank down at the shop. Maybe give him a call and check it out.