Hi - yes my b/f recently made me a fabulous fitted unit in an alcove for my 4ft tank. He made it to my design and it only took him a couple days to complete it all (few hours each day). It houses a 4ft tank above and underneath is a cupboard at either side with a central space for a 2ft tank. The electric socket is inside the righthand cupboard (just how it worked out). The cupboards are great for keeping all my aquatic bits n bobs tidy and there is a shelf for my fish meds. The cupboard doors are on soft-close hinges to avoid any shock to the fish by accidental slamming of doors LOL.
I will have to ask him later on for some details but, yes, I know he did use a good solid timber framework with various support batons. I have a pic of the unit mid-stage and the completed item but they are on my phone and I haven't figured out yet how to get pics from my phone onto here.
Will let you know if I manage to work it out.
The only thing I think we should have done differently is that the supporting shelf for the 4ft tank would have been better if it had been a bit deeper in depth rather than to the exact depth of the tank. I think it should have been at least a couple inches more than the depth of the tank to allow the tank to sit a couple cms away from the wall, in order for cables to run along the back, if necessary. As it is, my tank is right up against the wall at the back so I only have the choice of having cables running at either end of tank, down into the cupboards below.
But that's a minor gripe. I'm really pleased with how it turned out.
The great thing about building your own, is that you can customise it and design it exactly how you want it, in whatever colour you want. I chose white because our fireplace surround is white, so I wanted it to blend together as the recess is next to it.
Regards, Athena