I don't own an arcade monitor so I can't help you on that end but if you want to hook it into a TV or monitor (depending on what inputs yours accepts) I can help you (homemade supergun). Firstly buy a new Jamma harness. You can get them for like 10 bucks and the quality is way better than you'll ever build yourself. Like this:
I can't really recommend that particular seller because they sell xin1 MAME bootleg boards but for the sake of easier explanation I'll use them as an example. Then if you're hooking it into a monitor/TV with S-Video in, you can use a cheap RGB converter, like:
Try to get one like this that has the 2 different input sections... See in the bottom right where there are 2 white input sections, one is standard Jamma with R,G,B,Sync,Ground. The other is similar but it has Hsync and Vsync. That will come in handy if you enter the "beyond Jamma" market one day, which you will. Anyway, the most important things in this step is having separate color adjusters (labeled RGB Adjust here) and having the right input for your monitor/TV (composite and S-Video out are on this one). You can find others that have component etc. and higher resolution for higher costs. If you are using game boards that are far from 60 Hz output (like early 90's Williams games) you might not be able to sync correctly using an RGB converter to TV/LCD monitor, at least not with some S-Video setups I've used. It's common. The only way to for sure get correct syncs guaranteed on them basically is to use an arcade monitor... I don't have one so can't help you there. If you have a big old extra TV with S-Video in, I'd just save the money and use it... Anyway, moving on...
The next thing you need is a power supply. I wouldn't use a hacked old PC one but it's possible. Get a "Peter Chou" style one (new) for around 20-25ish. The hookups into the Jamma harness will be self-explanatory, most pre-made Jamma harnesses will even have the main RGB etc. already put into a plug that snaps into the RGB section of common RGB boards. My suggestion is you buy 2 Jamma harnesses. One you keep as-is for straight plug-in for Jamma boards and the other one you can hack up at will for non-Jamma boards.
Other than that you just need to build a control panel. No you don't need anything-pac. You solder (or, depending on how you build it) snap wires from the microswitches in the panel to the Jamma harness. Snap setup is better, obviously... It's really simple. I can help you more after you have the parts.
Edit: Oh and you need a multimeter if you don't have one already. Set the +5 on your power supply to 5.1 before plugging anything in and you'll also use it for continuance checks (everywhere).