The channel strips mentioned give you instant control of eq, comp, gating and volume/gain.
The interface is going to require a pc and then the plugs/software will offer the gain/eq/comp/de-essing etc...
Im not sure what your meaning other than you want to go portable. Are you going to be plugging into other peoples computers? I would imagine any studio you go to is going to have a interface and inputs, so if you want a consistent setup to plug in with, in addition to your microphone, the DBX above is covering it all and fairly "portable" I guess?
Unless you want something small like a Joe Meek VC3 1/2 strip size.