I have heard lots of good things about the akishop pcbs, but from what i gather there is a redesign coming and they are out of stock, and have been so for a while. I decided to go pads because: 1) Didn't want to wait for them to be back in stock; 2) so no use in the ps3 connectivity and 3) thought they were too expensive.
The pcb is designed to be put in custom fight sticks, so they can be universally compatible, so they only support 1p each. So for a 2p cp you would need two of them.
I got my pads from vpgames.com, they were like 23 bucks each I think. You can find good info on how to hack them on shoryuken.com, or you can pm me or haruman for advice. Its a pretty straight forward solder job, its a common ground pcb, so all you need is to solder the positive leads and a ground or two. I even soldered mine up so that the guide button lights up when the controller is on. All the inputs are digital, so no digital/analog conversion is necessary. The only tricky thing is soldering the guide button, since the spot is tiny. If you look on my project thread, you will see what they look like.
You probably have more PS3 games, but most of them you probably won't want to play on your cab. Most games these days use analog controls, and won't work well with the digital joys you have in your cab. In terms of Cab-friendly games, the xbox is better because there are a lot of good xbox live arcade games that play well, plus the shmups.