if you're handy i have a 55 gallon tank im getting rid of that needs to be resiliconed so you could put some baffles in as well....i know a glass guy that can help you out with getting glass to use as baffles.....tank is free as long as it is picked up, nothing in return is necessary but i wouldnt be against a frag of something that you could spare lol
Petco is running a sale on tanks. $1.00 a gallon up to 55g. So you can get a brand new 55 gallon tank for $55 then add some baffles and make your own sump.