I also made my sump from one of the designs on melevsreef. Here is the plans that I used it was very simple I just copied the last picture on this page. http://www.melevsreef.com/acrylics/sumps/glass/index.html He made his out of a 20 I just used a 30 gallon tank I bought from a thrift store.
Home Depot sells the acrylic pieces at a decent price and I just used silicone 1 I picked up while I was there. Make sure you clean the glass really good with something like rubbing alcohol first or the silicone will fail when you put warm water in (been there done that). Good luck and have fun!