Just get the regular Happs horizontal microswitch pushbuttons. Those will give you a good feel. There are also the Competition buttons, but I believe that the buttons on those are convexed instead of concave. That sort of button is common only on modern arcade games. I would go with the regular Horz. Pushbuttons.
For the joystick go with the Happs Competition Joystick. There are people here and there that prefer the Super or Ultimate over the Comp, but in all the time spent on this board, I have seen more people prefer the Comp. over the others time and time again. They are the best 8 way joy you can get from Happs.
Go over the
www.oscarcontrols.com Oscar knows his stuff. He does a side by side comparision of all 3 Happs sticks (Ultimate, Super, Comp) and in the end the Comp comes out on top.
Trust me on this one. I have comps on my CP and SF2 is incredible with them

jakobud