McIntosh MC2002 And MA6100,C30 0r C32

i have a MA6100, what would be the benefit if i switch out the MA6100 with
a C30 or C32, what is better unit the C30 or the C32. this is my first mac system

I service McIntosh in a huge Mac town; Nashville, and have had several of the units you mention either owned by myself or serviced on my bench.

The MA6100 (and its MAC1900 receiver sibling) is one of the better platforms to work with as it is 100% discreet transistor circuitry,all the major boards are plug-in cards (easy to tweak and service) and it runs cool as a cucumber, plus the sonics are surprisingly neutral and musical for an early transistor design.

The later units; MA6200/MAC4100 used early IC OPAMPS and I feel these add a glare to the sound that was missing from the earlier units.

Stay away from the C32 as it used the first generation of FFC (flat flexible cable) ribbons and these will be delaminating and falling apart inside (once you remove one, you may not be able to reinsert it as it's now split open!).
Good luck replacing them; no longer available from Mc and replacement FFC's are not easily acquired.
I had a 6100 for years. It is essentially a C-26, which means it is a very nice preamp. The amp section of the 6100 is no slouch either. I like the C-28, C-29 preamps. I had those too. Very nice. The C-29 probably has a little on the 6100, but not much.
Enjoy, they are superb products.