Help me choose interfaces for my first control panel

[rygar]

Well, I ordered all my controls, but I'm not sure which interface is the best for my situation. Here are my specs:

Control Panel
32 buttons, 4 Happ Competition Joysticks
Happ 3" Trackball
Oscar Spinner
(basically identical to this one, but with a few changes)

Computer
6 USB Ports
2 PS/2 Ports
Running WinXP, and all emulators are Win32 based.

Now for the questions, what is the easiest way to interface these? I want to run the trackball as my mouse in Windows, and I'd like to have a real keyboard in the cabinet. Also, is there a single interface can handle 32 buttons + 4 competition joysticks? I don't have a preference between PS/2 and USB, I'm just looking for the easiest thing to setup for a newbie. Thanks in advance.

[Apollo]

I-Pac4 and Opti-Pac both from www.ultimarc.com

[Mugzilla]

What are the 32 buttons? I am assuming you want 7 buttons/player, leaving you with P1, P2, P3, P4 start buttons?

[blue]

I'm going to go with Apollo on this one.
For that many buttons and controls the I-Pac4 will be your simplest bet and least amount of hassel.

[rygar]

What are the 32 buttons? I am assuming you want 7 buttons/player, leaving you with P1, P2, P3, P4 start buttons?

It's going to be set up very much like this:
http://jakobud.com/images/mamecab/cp_front_med.jpg

Two street fighter 6 button controls in the middle, and two 4 button controls on the ends. The extra buttons are for coins, start, esc, pause, and mouse. I need those since it will be running all sorts of emulators from NES to N64, and I'll need to escape fullscreen often. The Ipac-4 looks like a winner, thanks for the suggestions.

Edit: I forgot to ask, what exactly is needed to hook the Happ trackball and Oscar spinner to the Opti-pac? Do they include the necessary cables, or do I need to buy a special one? I'm trying to avoid buying cables and accessories I don't need. I'm trying to round up all the parts I need for my CP minus the wire which I can buy locally.

[Apollo]

You don't need anything extra, look on the ultimarc site for instructions.