monsta;
It appears you picked up some bug from ebay. Thunder thinks it has been corrected by ebay. We’ll get back with more info later.
I can’t reconstruct your list but here’s my response. The cheapo models are just that. Junk. They were the three bottom ones on your list.
I’d suggest you email the sellers of the top three (good prices, looks like to me), and ask them the sizes of the cylinders that come with the kits. This is important. If you don’t know about tube sizing compared to your dick size, ask.
I think also that you will be happier with a pressure gauge than not with not having one.
If you plan to pump with water, this is another consideration. Ask if those pumps would be damaged in water use. I’m not that familiar with the top three on your list.