You could make your own...
Lincoln, Plewis, Goldenrod and OTC list piston type suction guns, but I see no mention of country of origin for any of them.
The only review of the Goldenrod suction gun I found was on Amazon, and is disappointing.
On the only opportunity I've had to use one "recently" (6-8 years ago), I was broke down and bought one from a chain store (Oreily's, Autozone, Advanced, ... I don't remember, except it wasn't NAPA) it sucked in every way, except moving fluid.
For refill, a long enough section of hose can be adapted to the jug to gravity feed the fluid into the drivetrain item you are servicing.
Mightyvac makes a larger volume collection canister (2 Qt. IIRC) that should drain a moderately sized diff or trans in a couple goes, as well as a combination vacuum pump and receptacle that should handle all but the largest in one shot.
Nice thing about the Mightyvac, it is useful in more than your stated application.