Building in 1590As, with a little patience, is quite easy actually. I recommend you buy two enclosures, one painted if you get them that way, and one not. Use the one that isn't as your practice one and learn about the tolerances you have in drilling. Then make your masterpiece.
The only problem I have with 1590A circuits is that I can't/dont use them. The enclosures are too small for me to really feasibly use in a pedalboard! I find that once you add the width of the jacks coming out the sides, you're not too far from a 125B then, and because I do top mounted jacks on those, I'm getting about the same square footage with more room for controls and things like Batteries if I need them.
That said, it's just me like that. MANY people love and use 1590A pedals, I just don't. 1590A's are really handy for things like tap tempo boxes, buffers, and splitters.
Jacob