Reply to Portable controller (or mixer with MIDI?) for 4 channel mixing a la X-Session Pro?

I'm currently using an X-session Pro to control Traktor's internal mixer and it's nearly my ideal solution, but lacking in a couple of ways: 1) the EQ knobs on the outermost channels (1 & 4) don't have a center indent - slight annoyance, 2) I'd like a filter knob for each channel on the mixer as well.

I'd be willing to spend a reasonable amount of money for a controller that was better designed for mixing 4 channels, but can't find anything matching my criteria:
1) reasonably portable so I can bring it to a club and fit it in a booth (I want to carry on using the internal mixer in Traktor, much easier plugging in one stereo pair rather than 4 channels to the club's mixer!)
2) MIDI output (when considering buying a 4 channel mixer a la DDM400 and mapping it)
3) designed for mixing (goes without saying but I mean things like having center indents on the EQ knobs - so something like the UC33e fails here)
4) No need for effects or transport controls - just volume and EQ and filter

A few buttons would be useful but not a definite requirement - I will be using my iPad (in theory) for transport and effect control. I'd hoped Faderfox might have something fitting the bill, but their 4 channel controller only has one set of EQ knobs, wtf!

Any suggestions, either mixers or controllers? Of course, I know I won't be able to resist the S4 and this will all be a moot point, but humour me