So, I'm in the midst of converting an old arcade cabinet into one that will have a PS2 as its "heart." For the custom controls, I was just going to use a MC Cthulhu board or the pcbs from some Tekken 5 Hori sticks, but was disappointed that so many of the arcade/2D gaming compilations for some idiotic reason were only compatible with the fully analog Dual Shock 2 controllers (for the life of me, I don't understand why Taito Legends 1 or Mega Man Anniversary collection couldn't be compatible with a digital-only pad, like the aforementioned Tekken 5 stick or any of the much easier to hack PS1 dual shocks).

So, having browsed many padhacking threads and google searches, I am still confused, and ask, has anyone found a relatively easy way to build a PS2 controller fully compatible with all PS2 games (I can't seem to find a comprehensive DS2 hacking tutorial)? Or should I should I just forget about it and play the games that ARE compatible, like the incredible Capcom Classics Collections 1 and 2?
(by the way, I am starting with PS2 because I have one to spare... I figure with a converter I can easily graduate into MAME-land later on if I want to).
Thanks in advance for any advice!