The two leading brands in airgun stirrup pumps are Hills and Fx.

I have had an Fx stage 3 for over 10 years I even fill my Gunpower Stealth bottles that are 500cc. It has worked well and I have checked inside air cylinders and no sign of corrosion with long term use. So I would happily recommend an Fx stage 3.

It was also bought from a member on here so its secondhand.