do yourself a favor and skip the xarcade. they are great units for what they are, but i can tell you from experience, you will regret it in the long run if you go this route.
i bought an xarcade 2 player unit a few years ago. when i got around to building a mame cabinet, i attached the xarcade unit to the cabinet...it worked, but looked like crap. then i decided to cut my own panel and use the components from the xarcade unit. this worked much better, however due to the way these units are wired, they are a nightmare to work with. the wires are too short, and they dont use a common ground like most encoders, so the wiring is quite messy. i have used it this way for about 2 years now and i am finally sick of it. i am on the verge of placing an order for new sticks, buttons and encoder to do it myself, the right way. the sticks and buttons arent bad, and can be purchased for a reasonable price. i dont know what their trackball is like. it may seem overwhelming to think about doing it yourself, but this forum is an immense help. button wiring is easy once you have a very basic understanding of how it works. get yourself a real encoder and do it right.
the woodworking aspect is much easier than it sounds too. when i did my project, the only tools i had were a dremel, a $20 single speed drill, and a borrowed jigsaw. just take your time, search the forums and dont be afraid to ask questions. do you have any friends/family members that could help you? I have a strong background in computers, but very little woodworking experience, and very little knowledge of mame. but i found this forum and asked questions, looked at the project announcements for inspiration and i managed to make my own and i am pretty happy with it. sure it isn't perfect, and that's why i am redoing it. you learn as you go...don't expect perfection your first time through. build it, try it, tweak it, rebuild it, repeat until you get it just the way you want it.
teh xarcade units are great for someone who wants a desktop control panel, but for use in a cabinet, they are more headaches than they are worth. check out the many places to buy parts, ultimarc, groovygamegear, and teh buyselltrade forum. i have purchased from divemaster and he has been great. when you break it down, you can buy the parts for around the same amount of money, or less and have it be the way you want, with the colors you want.
just a suggestion....i just know that if i had to do it all over again, i never would have used the x-arcade, i would have made it myself the first time.