There are some free plans floating around too (search this forum). But if you are not an expert carpenter, than you might just want to consider refitting an existing cabinet.
But if you ARE building from scratch, you don't really need plans to do so. The only really important things are that the control panel, and marquee are at appropriate heights, and that the monitor is mounted at a height or angle that allows for easy viewing.
So, go out to a few local pizza places until you find a cabinet you like, then measure the heights of the control panel, where the monitor is, and the marquee, and then you should be fine.
There is really no magic formula to it. I own (and have owned) dozens of cabinets, and the designs are all over the place. Cabinet design is not rocket science.
Your design will be fine as long as the machine isn't too tall (most are 6' or slightly less), and the control panel is at a reasonalbe height, and you can see the monitor. Also, one BIG problem with most "pay" plans I have seen is that they produce cabinets that don't really look that authentic (2 piece cabinets are not authentic, sorry to all who built them, they just aren't).
If your budget is limited, then consider doing a refit, as it is much cheaper.
A few dimension suggestions if you do go it alone.
Most classic 1980s cabinets were right around 25" wide, very few varied from this by more than an inch. (making the front section 24" wide, and then using 3/4" sides is perfect, and seems to be what most game manufacturers did). Newer cabinets are not much wider, figure a max of 29" wide for the basic cabinet. You can always hang the panel off the edge a bit for extra control width.
If you go with a overhanging control panel, then no more than 3" overhang on each side, and you study the dedicated Gauntlet and TMNT cabinets to get the idea for what the general shape of a 4-player cabinet is. I have seen too many 4-player cabinets here that were setup in such a way that player 3 and 4 could't really see the screen.