42" tall is pretty tall! My old stand for my 20g was 42" tall, and I felt like it was excessive. I always had to stand to view the tank. None of my chairs went up that high were I could just lay back and view it. My new stand I built purposefully at 30" tall. One foot lower made all the difference to me.
I don't have a whole lot of room underneath my stand, but I definitely have room for my calcium reactor and 5lb CO2 cylinder and other junk that I probably don't need right now.
I think you could save some money by building your stand just 36" tall... that's three feet tall - you could use one 2x4x8 per two legs in that case. Depending on the look you want, traditional or whatever, you can do it for relatively cheap. Look at ADA style stands - and look how simple their stands are. Something like that can be done relatively cheaply.
With your tank only being a 110g, building the stand strong enough where you don't have to have a middle brace is pretty easy. Just build it out of 2x6's. I'd take a planer to them and I'd also rip the sides with a table saw to get rid of the rounded edges... a pocket hole kit would allow you to make all of your screw connections on the inside of the stand. Premium pine takes a really nice stain, if you treat the pine right while your working with it and sand it smooth.
If done right, you can build your stand with 72x36x36 for roughly $200-250 if you have the skills and already have a few tools.
Are you making the tank rim recessed?
