I'd recommend getting a legit joystick if you're going to be serious about it.
TE sticks are $170US, but you get what you pay for. The cheaper sticks don't last too long.
If you want to be real cheap- Saitek offers 6 button PC pads that will do the job for $20. You get what you pay for. The $50 pads for sale SF4 branded aren't any better.
As for the quality of SF4- it has issues but by fighting game standards it is quite good.
Really, if you're a fighting game fanatic- consoles are better (and one of the few reasons to own a console), since PC's don't get the games usually.
Thanks for the replies.
Consoles never convinced me. I build my own PC's and trust me, no consoles come close.
If you're not aware of it, the SFIV arcade "machine" is only a very basic PC (Dual Core intel... blah blah). My 2 year old laptop has better specs, i ran the benchmark tool and it runs SFIV at 1680x1050 smoothly.
Consoles are not better for anything. Developers chose to start developing more for consoles, and it's sad to see awesome franchises turning to crap because they have to cater to the consoles crappiness.
Not even the controllers make sense, you have better quality and more variety of all kinds of controllers for PC than for all the consoles combined.
I even thought of building my own Arcade Stick, but i just moved to Australia recently and right now i don't have the tools or the time to do it.