Definitely the way to go is a Wacom cintiq companion, not the companion hybrid. The Hybrid can double as a screen when you plug it in to the computer, but when used alond it is an android tabled and cannot run photoshop. Photoshop is really the only program you'll ever need. You can try other shit, but eventually you will just be working your way up to photoshop.
The Competitor really is the Microsoft Surface pro, the main difference being the larger border on the cintiq (which is basically for resting your hand on while you draw) and programable buttons.
These tablets differ from other tablets in the programability and pressuer sensativity, and the fact that they are windows 8 and not Android OS.
I'm starting a shop and Will be buying a Cintiq for the shop for sure. At this point, I think it is vital. If you want to get your toe wet however you can get a Wacom intuos5 at best buy for like $350 or cheaper online. It is a little difficult to get over the hand eye coordination exercises that you can do that will get you over that in a week. The advantages are that it is a lot cheaper, your monitor is probably bigger than a tablet screen and your hand is not in the way.
Just something I've had a lot of experience with in the last couple of years.
I think I'm going to do some videos on digital topics like this if anyone is interested.