Ive just built a phattie desk out of ridgeons structural timber joists....
I incorperated 2 26u racks, space for a mackie 24, 3 2u racks above the mixer and a shelf that slides back so you can get to the inserts, 2 drawers, speaker shelves, pull out keyboard shelf etc etc... Took about a day with a skilsaw and battery drill, but it looks the dogs bollocks its sturdy as ****, and it cost under 80 scroats - I'll post a pic on here asap... I definitly recomend getting creative yourself. Even if you have to hire the tools, it'll still work out much cheaper, and better too as its fully customised... get a builder mate round if you are a bit unsure and let him shag yer missus if he helps you...it'll be worth it!

Ps. I bought one of those (jerka?) ones from ikea and the bolts were all missing - Took them 4 months to order me some in!!
it wasnt half as good as what ive got now and was a bit more quiddage too.. but they probably are the next best alternative to building your own