I know you said you want to build it but, personally, I agree with pointdablame. Buying a cab was easier, cheaper and much more expedient and I'm glad I did.
Arcade projects are those kind of projects that never seem to be quite 100% completed. There's frequently just one more change here or there that you want to make. I've been working on my upright for a couple years now and it's still not 'done'. I can't imagine how much LESS 'done' it would be if I built it from scratch.
If you have access to tools, space, friends etc, then I think building is cool. But with all the cutting, clamping, gluing, sanding, painting, sanding again, and more that's required, I'm very happy that I bought a used cab.
If you are really concerned about whether you have the woodworking ability, and if you don't have all the tools you need.. just buy a cabinet.