Similarly to John, I used 3 kitchen units from my local DIY store to make an 8' long worktop (http://www.apug.org/forums/attachmen...tachmentid=914). They are screwed together through their sides and pulled out about 9" from the wall to give the width needed to fit the enlarger. A 2x1 strip of timber goes along the wall behind them at the same height as the top of the units. The top is a counter unit which is screwed to the timber strip on the wall and screwed to the units using the brackets that came with them for fixing the normal kitchen counter top. It happily held two 4x5 enlargers (now only one).
See the Darkroom Portrait thread for tons of ideas (http://www.apug.org/forums/forum43/10966-darkroom-portraits.html).