I did a coast to coast on my 144 gallon. Cost was pretty much nothing. I went and had the glass cut at a local window shop ... I think it was about $60 total for my 5 foot tank.
http://www.canreef.com/vbulletin/showthread.php?t=96736
I'd go with the Bean like Grizz is gonna do. I went with the BeanAnimal and its the most quiet hassle free setup I've ever had.
The Durso is noisy, the Herbie needs constant adjusting ... but the Bean is fail safe, its silent, and it auto adjusts for a very wide range of flow. The only downside to the Bean setup is the initial plumbing costs being a bit higher. Because you have 3 standpipes (the full siphon, the over flow, and the emergency standpipe) you need a bit more PVC than with the others.