Well, I've been using the Korg ESX-1 as a combo sequencer/keyboard, but it sorta sucked for the later use. So I've put together a new front end built off of some ancient tech I had tucked in the garage.
Starts with the iConnectivity iConnectMIDI2 (non-plus). I originally got this when I reviewed it for Recording Magazine, and it has been in use on-and-off over the last few years. For all of the things that it does, including iOS connectivity, computer-to-computer connections and MIDI thru functionality, I'm most entranced by its ability to be a MIDI host for the host of USB MIDI controllers I've got.
I've got a nice keyboard front-end for my teaching modular. Given that the whole thing was hidden away in the garage, I think I scored - but if I needed to redo this from scratch, all of the components could probably be bought off of eBay and Amazon for about $150 or so. Hella deal until Paul Schreiber comes out with that new MIDI module (which has a USB host function).