I’m looking to upgrade my Magnum Dynalab MD106T???

I doubt very much that the Accuphase would be better. Nowadays there are very few top quality FM broadcasts that would justify paying that much for a tuner. I use a Magnum MD90 with an attic mount yagi type antenna. Save your money, that tuner that you are using is top of the line!

Your “true differential” balanced output requirement will significantly limits your options.  

Other than improve your antennae location/position, the Marantz 10B or the rare REL are the final frontier.  A close second would be  Modaferri modded tubed Macintosh.

I must admit my MD106T is sounding nice today/last night  as I have been listening for hours and I think my relatively new Amperage tubes may be sounding better with some playtime or maybe the reception is good now. An upgraded antenna would be nice but is my  MD ST-2 antenna not a decent antenna? I don't think we would be allowed to install something large on our roof? We own our home but live in a town house complex. It would be nice for a better antenna. Any advice on an upgrade to an MD ST-2 antenna?

McIntosh MR87 or MR88.