So I've had a decent MAME cab toiling about in the corner of my basement for the last 8 years or so. It's not that impressive. It was a bit of a hack job that I stuffed into a TAITO home arcade I bought from a yard sale for $25. Never mounted the monitor right, everything is just kind of floating inside, and some awfully embarrassing soldering work. I just recently finished up a pincab build and as a wise older man (and a man with far more power tools than his early 20s self) I've decided it's time to update this poor little sad cab.
The original plan was to use the old computer parts inside the old machine and just rebuild the cabinet to fit a new control panel and monitor. Well, I'm bad at restraint and that quickly went out the window. So all new pieces it is! Computer hardware list, ASSEMBLE!
Main monitor: Vizio E32-D1 32"
Let me explain this choice. I know it's a little bit big, and far better refresh than I would really need for a MAME cabinet, however! I want to be able to play all the newest PC fighting games (ie Street Fighter V) in addition to all of my other arcade and console favorites. So I splurged a bit, this is a recurring theme.
Secondary monitor: LG 29UM67P Ultrawide 29"
So excess is a bit of theme here. I was researching different ways to make a cool new marquee outside of the spray painted plexiglass I had on my original cabinet (I said it was hack job already) and I thought, golly, wouldn't it be swell if there was something that would dynamically change to the marquee of the game I'm playing! And sure enough there is! If I can do it... It's going in the cab!!
Third Screen:

I'm also considering putting a third screen into the control panel to display controls for the games, this is a big maybe as it seems really unneeded, but that makes me want to do it even more.
Video card: ASUS GTX 970 TURBO-GTX970-OC-4GD5
Again, waaaaaay too much for MAME and emulators, but I want to be able to push newer PC games at pretty high settings at 1080p so I wanted to get something that could do that. This seemed like an excellent choice (and I may end up getting another to upgrade the GTX 720 that's in my pincab)
The other stuff:
8GB of RAM, I'm thinking this is going to turn into 16 before the project is finished
650W power supply, Why not?
Core i5-4690 Haswell Quad-Core 3.5 ghz, I feel I may have skimped a bit on the processor, but I think everything will turn out good. We will find out in the near future.
DIYPC Alpha-GT3 Case, Nifty open air bench case so I don't have to worry about ventilation of a case in the cab.
So there's the PC components. I think that should be pretty well setup in that department. I've got all that in my possession and I've got it all built and just need to get the software setup. I'll be using Hyperpin as my frontend as it seems to have everything I want this bad boy to do and is what I had used previously.
Control Panel:
I'm planning on a 4 joystick setup with an Ultimarc Ultimate I/O running it. I'm planning on 4 RGB joysticks, probably the Paradise RGB joysticks, Player 1 and 2 with 6 buttons and 3 and 4 with 4.
RGB Novagem buttons for credits from GGG that Randy JUST added to the site because he's the awesomest dude around. (I really need the credit buttons to match the turtle colors in TMNT)
Pushbuttons is where I sadly hit a wall. I was planning on using the Electric Ice concave RGBs for all the player buttons and start buttons, but sadly Randy says they are going to be out of stock for awhile. I'm at a loss a bit as I really love these buttons as they are what I have on my pincab. He has plenty of the convex buttons, but I don't really know how I feel about those. I may switch to the HOKU buttons from Paradise, but they told me they will be adding a new item that will come with the connectors for the Ultimate I/O in the near future, so I'm holding off on that for now. Hopefully I can come to a decision soon on that, I may have to get a few different buttons and do a test board to see what I like the most.
Cabinet
I'm planning on building the cabinet out of 3/4" MDF. I don't have a design idea at all yet. I'll probably draw some things up tomorrow, but I'm thinking it is going to be based on the TMNT 4 player cab, but a little wider to support the monitors and of course my control panel will be wider than the TMNT panel. The only thing I'm worried about is potentially being too close to the 32" play screen. Maybe I will set it back a little further into the cabinet than a regular monitor would be as I really don't want to turn this into a pedestal style.
And that's where I'm at right now! I'm going to work on some drawings tomorrow and hopefully share some ideas with you guys as I go and get some input. Looking forward to this build and really want to get it done within the next month or so. We'll see how that goes! Feel free to hit me with help or criticism, I take both happily!
Good journey!