It's really not that hard to do yourself. Just draw a detailed drawing of the stand both front and end view, first mark in your over all size: height, width, depth, then you have to take into account the thickness of the material you're using.
for example, if your cabinet is 900mm long and you're using 21 mm MDF then your base would be 858mm long.
Remember that if your tank is over about a meter long then for safety reasons you need to have a center division that goes all the way to the floor and supports the top.
usually your cutting list would look like this
2 x Ends 750x450
1 x Base 858x450
1 x division 700x450
1 x top 900x475
and so on and so forth, the height (or width for horizontal pieces) is always listed first.
The same concept applies if, like Smidey, you decide to build a timber frame stand.
Hopes this helps.
Carlos