I've been deliberating this exact question. I finally pulled the trigger and went with the Comline DOC Skimmer 9004 - Tunze. Actually was just delivered today.
I haven't found a better piece of hardware out there than it and it does fit. From left to right in the back chambers of the 30L I'm doing.....
1. Left overflow chamber - Tunze 9004
2. Left Media Chamber - inTank Fuge Basket with a custom cut block of Marine Pure
3. Sump Chamber - Return Pump, Heater, Monitor probes and place to toss a media bag of Chemipure or similar if needed
4. Right Media Chamber - inTank Fuge Basket with a custom cut block of Marine Pure
5. Right overflow Chamber - Media basket filled with Marine Pure Gems in lower 2 chambers and top chamber/tray reserved for situational use of floss.
Trying to max my biological filtration with the high efficiency of the Marine pure blocks and gems along with a solid skimmer. Tank will have a conservative amount of live rock and a 2" sandbed.