any recommendations on playstation2 gamepad -> arcade controller hack?

[vanRijn]

As the subject says, I am looking to venture into my first arcade controller hack, yay!  I originally thought that I'd use a couple of gravis gamepad-pro usb gamepads for this, but after my wife has said a couple of times that she's thinking we might want to get a playstation2 for our kiddies, I'm thinking that I should build this arcade controller (well, 2 of them), so that I can use them on the ps2 as well as our PC.  

So, with that in mind, I'm hoping that someone here can recommend a good controller to use for this.  I have read that most of the playstation2 controllers are analog and that that's not a good thing when working with real Happ joysticks/buttons, but I don't understand why this is, or how to stay away from getting gamepads that won't work with the Happ controls.

I have already bought a $9.99 StormChaser game pad for that says it works with playstation1 or playstation2, and made sure that it works with Radio Shack's $9.99 PSX->USB converters, and it seems to work swimmingly.  But the innards look rather complex and being that I've not done this before, I want to give myself as good a chance of not screwing this up completely.  Also, I've read that people like MadCatz controllers for these kind of hacks, but I've not seen them specify whether or not they use MadCatz PS1 or PS2 controllers.

So, anyone with recommendations?  I'm not opposed to being told that I should hack a PS1 (is PSX the same as PS1?) controller, and that that might mean that I won't be able to play some of the newer games with my arcade controller.

Thanks in advance for the input!!!