So, the basic idea was to go as inexpensively as possible:
1) Use an extra PC motherboard/cpu/ram - nothing to purchase.
- I had one with an AMD Athlon 1350+ CPU and nVidia GeForce video card with 1GB RAM.
2) Use one of my extra Harddrives - nothing to purchase.
- Started with this idea, but then figured that this is going to be a portable unit and the drive will be rattled around during transportation and also might get jostled during gameplay. Also, a constantly spinning drive uses power and generates heat (which I want to minimize). Got the idea to try:
2a) Use a thumbdrive! Tried getting XP installed by creating an nLite image and followed the directions on getting it to install to the thumbdrive found online, after spending days trying this, gave up on it and tried:
2b) Linux! There are many linux thumbdrive implementations, so I figured why not? I know some linux (by no means a guru), and tried ubuntu. Got it installed and then downloaded sdlmame and after a lot of updates and configuration, finally got Wah!cade frontend installed and working. Was configuring this all while visiting my wife's grandma (3 days spent), on the laptop that I had with me. Had some sound stuttering issues and wasn't able to resolve them and I figured I would do it when I got home. Plugged the stick into the pc being used for mame and it ran like a dog - we're talking maybe 5 frames per second. Couldn't get it to work right, so though I would try a less intensive linux version:
2b1) PuppyLinux. Several days wasted on getting this thing to work. Back to WinXP.
2c) So I used some Amazon gift certificates and picked up an 8GB Solid State IDE drive. No moving parts. Shock resistant. No heat. Superfast. But $100 added to project cost.
3) Arcade parts:
3a) Buttons and joysticks (happ super) from GroovyGameGear.
3b) Trackball - wasn't going to buy a new one originally. Thought I had a PC trackball lying around, but this wasn't the case. Looked into getting something from eBay, but the pricing on them was close to what xgaming was offering for a new 3" trackball unit so I bit the bullet and purchased one. As a bonus, it came with 4 arcade buttons (for mouse controls), but I can use them for admin controls. Added $60.
3c) Spinner - wasn't planning on this, but after trying to play arkanoid and tempest with buttons, determined that this is a must. Looked into doing a mouse hack for a spinner, but the instructions and work was so complicated that I just got one from GroovyGameGear. Added $70.
3d) Keyboard encoder - I was going to do the keyboard hack idea. I have lots of keyboards available to me. But after looking into all that is required (mostly time) I dropped the $35 for a KeyWiz unit. I am not afraid of soldering, but I had no desire to sit there and map out matrixes. Also, using a dedicated encoder will reduce the amount of wire needed to hook everything up.
As you can see, the "inexpensive" requirement is going out the window...
4) Power supply - use the one in my computer case.
5) Fans - use the ones from the computer case. Will probably have to by grills for it.
6) Speakers - use the 3" speakers from a set of pc speakers I have.
6a) Found out that the motherboard doesn't have a "speaker" port but a "line out" port. This means that I need to have power for the speakers. I don't have a set that I can cannibalize...
6b) Thank you Target! On sale, set of powered speakers, originally $15, but on sale for 5$! The actual speaker units were junk, but I just needed the power module. Also they have fabric covering which I was able to pull off of the shells and can use for the console.
7) Attaching the control panels to the unit. Had many thoughts on this, like using 25-pin d-subs and such, but after reading the build for the "modular" panels that use RJ45 jacks, that made sense (I have lots of cat 5 cables around). Will need up to 3 patch cables (for the 2player panel) and 2 for each of the others. 1 of the cables will be for the 2 joysticks, then another cable for the player buttons (with one cable housing the ground pinout). Purchased a bunch of "european" style terminal block from Radio Shack to terminate these cables on the panels. Will use 20 or 22 gauge stranded wire for the actual switch wiring. The spinner and trackball use USB so no worries there.

Material for the actual unit - while I wanted to go light, I decided to use MDF. I hate particleboard. I could have used plywood, but I was going to be painting this and MDF gives smoother surface. Using 1/2" MDF. I'm sure I will need carry handles on the sides of this thing...
Anyway, I cut out the panels last week. Went well except for the angled sides - had to use a jigsaw for that so have a bit of sanding to do to get them even. On vacation now so that will resume when I get back. Will have pictures. Now I'm working on front ends for Mame. Tried Mamewah, but think I might go with Mala. Designing layout to use the black/gold theme.