Red Cherry Shrimp are not aggressive like Ghost Shrimp. I've only ever been able to find any for sale online or at my local fish store. Red Cherry Shrimp are great starter shrimp because they are pretty hardy and left under the right circumstances breed very easily -- which is why you shouldn't buy a TON when and if you do buy some.
Sometimes Petco offers Crystal Red Shrimp, which are one of my favorites, they're not aggressive like Ghost Shrimp either but they are extremely sensitive to water parameters and it's difficult to avoid other fish picking at them. Of course that can happen with all shrimp, but at least Ghost Shrimp and Red Cherry Shrimp are way cheap comparatively. So just a heads up incase you stumble upon those, I wouldn't fully suggest starting out with those.
I've also seen Bamboo Shrimp at Petco (also called Singapore Shrimp, Flower Shrimp and a few others..) I wouldn't suggest those for that size tank, maybe a 30 or so gallon tank with a nice strong current.
The last popular one are Amano shrimp, which like the Crystal Red Shrimp are sensitive to water conditions and they are aggressive, possibly more aggressive than Ghost Shrimp.
If you have any other questions about other shrimp, I should be able to lend some advice, I've kept quite a few varieties..and like the other members I suggest the Nerite snail! They're fabulous.