55 wet/dry, fuge advice needed!

Just wanted to get some input from those that have or have had a 55, what size aquariums will fit under my 55? It is already set up and is pushed against a wall, so I am wondering what I can squeeze into the stand for my wet/dry and fuge. Would a 30 tall work? It's pretty tight, that's why I wanted to check with everyone and see. Let me know!

 

Glasscages.com - Home can make whatever you want

 

under my 55 I have a (approx) 40 gallon black Rubbermade container. I put it under there and it has cat littler in it, getting ready to do a fuge/sump. My old PC 36" lights will fit perfect on top of it and they have fans built in...

 

A 10 Gal sump and a 5.5 Gal fuge or as Cuttingras mentioned containers of that size give or take. on the fuge .

 

I was planning on using rubbermaids, just wanted to see if anyone knew of any glass that would fit under there. Thanks all!