MC or MM + SUT?

Hi folks,

Zeroing in on my first deck.  
Having no experience or knowledge about decks, I did my research and asked opinions. 

Was about to go with a used VPI Prime Scout.  
Then I looked at the Technics 1200 G.
Pulling the trigger on a last minute find: Open box Rega RP8.

The research has now been focused on a decent phonostage.

Is it better to get a MM/MC or a MM with SUT?

I have a few of each type of cartridge.

Your statement of “I have a few of each type” would lead me to look at the MM/MC phono preamp option.  The premise for that choice would be the multiple MC cartridges and their individual requirements for optimal performance would not necessarily be provided by a single SUT.  Many phono preamps with MC ability provide multiple loading options and possibly multiple amplification settings that would be more versatile in you described situation.
Most of the phono stages on the market are MM/MC.
If your cartridge is 0.2 mV or higher you can use it with most of the MC phono stages, for lover output you will need a phono stage with higher gain.

SUT is a different flavor, only you can decide what you like with your carts in your system. 
Matching SUT to a cartridge impedance is also very important, this SUT for example can handle carts with 3 - 40 Ohm impedance range. 

In my opinion you have to start with MM/MC phono stage, you need an MM phono stage for a SUT anyway. 

P.S. Besides the SUTs you can use active headamp (with all LOMC) or very special current-injection phono stages (for low impedance MC only).