Kit flat enough for room measurement?

Hi,
Which (if any) of the SCA kits are suitable for use with Room RTA? (e.g. NADY CM 100 or equivalent mic with ETF or FuzzMeasure).
I have a J99 currently, but its definitely not uncolored. I'm wondering if freq response graphs / distortion specs are available for the various preamp kits?
I know the C84 and T15 are probably the best candidate for this, but are either flat enough to be used with RTA? Which is *more* flat/transparent, the T15 or C84?
Thanks
Which (if any) of the SCA kits are suitable for use with Room RTA? (e.g. NADY CM 100 or equivalent mic with ETF or FuzzMeasure).
I have a J99 currently, but its definitely not uncolored. I'm wondering if freq response graphs / distortion specs are available for the various preamp kits?
I know the C84 and T15 are probably the best candidate for this, but are either flat enough to be used with RTA? Which is *more* flat/transparent, the T15 or C84?
Thanks