there are several in the market. They look like the HTC one to me. 99.9999% of apps are going to work on the phone even if the app doesn't specifically say it will. It's still an HTC phone just like all their other ones.
If you go to the market there is a Gingerbead Keyboard app. If you don't like that my favorite keyboard is Swype. I use it instead of the stock Gingerbread keyboard. You can get it by going HERE.
Incorrect, I found one on the market that works. However I had an APK that I've been using since my Droid 1 that worked. Wouldn't install on my Thunderbolt. I used to use Swype but I made way to many typos so I switched off it.