HELP please... do I have the right tool?

I just got handed a job I'm not sure I'm ready for. My company bought
a Mikmaki JV130 SPII inkjet printer for printing signs. Our customers
like this new capability, but they want really accurate colors.

I can't get a profile for this printer for our paper from the paper
mfg or the printer mfg, so I thought I would make my own.

I calibrated the monitor with a Colorvision Spyder 2. Then I bought a
Colorvision PrintFix Pro package with a spectrocolorometer.

Only problem is that it seems this package is only able to make
profiles for RGB printers, but not CMYK. Is that correct?

We make our signs in Illustrator, and most art comes to us in CMYK
format. To further complicate things, the art goes through a RasterPro
RIP to get to the printer. Mimaki packages profile making software
(Mimaki Profile Maker) with the printer, but it doesn't recognize my
Colorvision 1005 spectro. It only seems to like Gretag or Xrite
spectros.

My question is, is there a way to get this package to work for my
setup? Or do I need to buy a Gretag spectro and use Mimaki's software?
I can only seem to make ICM profiles.

Thanks!

Stew