I have a surface pro 3 and I really dislike using Photoshop with it. The pen is too laggy for how I work.
I do love my Bamboo though--some people don't like that whole drawing on the tablet and having it show up on the screen but I'm convinced that a few hours of practice and your brain will get used to it.
Anyway, computer specs: I can give you mine when I'm on my home computer if you'd like but really you are going to want about an i5 (or equivalent) processor and as much ram as you can get. 8GB would probably be fine.
I'm not a computer guy so I'm not 100% sure how the video card factors in but I'd imagine that any one within the last several years should be good.
That brings up the question: how old is your computer? Probably any current mid-level out of the box (that is, non-custom) computer will be really good for you.