I guess I’m not the only one burning the midnight oil 
I’ve used a Valve base from Orbit (link) with a “standard” Valve Box (link). Keep in mind that a standard box will likely be too tall for the depth of your valves. Most stores will carry other valve boxes that may fit the Orbit base but are not as tall, such as this one from Lowes (link).
I’ve also bought some loose stone (as cheap as I could find) to put underneath to aid drainage (and keep the vales hopefully dry).
Cheers,
Gene
P.S. If you go back and look at my install (link), you will notice that originally I was planning on using a smaller box (first two pictures), but had to switch to a larger box at the end (next to the last picture).