Digital BW, The Print

I'm about to take the plunge on an Epson C88+ and a set of the MIS EZ
B&W inks, but I was hoping you guys could clarify something for me.

From something I read on Paul Roark's site, I got the impression that
the cyan, magenta and yellow inks are all the same density in the EZ
B&W set (the only difference being the chip on the catridge for the
various color positions).  Is that correct?

If so, if I intended to buy the spongeless refillable cartridges &
bulk inks, couldn't I just buy the appropriate photo black or eboni
black and then just get one bottle of the grey?  I'm just puzzled
because inksupply.com is selling the bulk inks under different item
#'s for the C, M & Y positions.  I was hoping to be able to just buy a
pint bottle of the neutral to fill the C & M and a 4oz. bottle of the
warm to fill the Y position.

Oh, and just to clarify, the refillable cartridges take 15cc of ink,
so about 1/2 ounce?  I just can't believe how cheap the bulk inks will
make everything -- too accustomed to buying $30 Epson print cartridges
that only last a short time!

Thanks for your help!