Mini-USB is fairly standard these days for connecting to portable stuff. Most manufacturers have figured out that proprietary cables aren't worth it.

I have to pull out the CPU to get at the back to remove the one(s) I want

More recent PCs have USB ports on the front. If yours doesn't and you've got a free drive bay, $20 at most will get you a suitable USB card with front-panel sockets. Or get a USB hub as suggested above, which will give you a bunch of USB sockets which you can position somewhere convenient to avoid moving your PC. It's like power sockets in your home - if you find you don't have enough, you can add another socket in the wall at the cost of some technical stuff taking place, or you can run a multiway extension from an existing socket if you accept slightly lower performance. Or you can live with having to move the sofa every time you want to plug in the vacuum...

Graham.