I know you said you wanted your pump submerged and for that I can't offer any advice but if you don't
have to have your pump submerged
here's a res that I plan on getting that looks very nice. They basically look like the Tank-O-Matic's but have much better flow. The company just recently setup this english version of their site
http://www.cstec.biz/en/ so that us english speaking peeps could get info on them since they are based in Taiwan and their main site is in Taiwanese
here. I'd suggest you read these threads over at the overclockers forums (where I found out about these) to get some more info about these reservoirs if you're interested....
This thread was started by a guy with an eheim 1250.
This guy has a laing d4 and custom designed his res from the same company. It's like a like a tank-o-matic with the flow design of a t-line sort of. He said that this one cost him $20
. This is the design I plan on buying.
The guy in the first thread says that you can buy attachments so the res will fit on a L40,L30,Mag3 & 1260 and I think they have attachments for the 1048, D4 and MCP600 as well.