Depends on how your current workflow is, and how 'faithful' the tunes are.
Personally I have a MIDINES (among many other hw boxes) and MIDI sequence everything old style using from Logic X. I simply prefer to compose with MIDI, drums and all. To gain extra isolation and control the final pass I solo each voice and multitrack. The MIDINES takes the drums / rhythm role on pretty much every track I do.
Yes as noted above, the MIDINES has a very good midi implementation, all those CC controls, and those awesome DPCM samples!
Twisted Electrons newest "hapiNES L" has a MIDI implementation so you don't have to use its sequencer which makes it somewhat comparable to MIDINES (not quite).
If you're just after leads & fills another hw box for consideration is "Arcano NES Chiptune Synthesizer". I also own this and for doing env and vibrato stuff, it is much so easier than programming a bunch of CC in the MIDINES case.
From your description both might be a good fit.