I've also got a Magnepan Unitrac Arm. I also have an Oracle Mk III with full Brooks Berdan mods as well as a Rega P3 TT.
The Unitrac has been mounted in the Rega since I put a Graham arm in the Oracle.
I bought the local dealer's personal Unitrac with the full dealer kit, & so have a few spare everything, especially lead wires. If you need anything, let me know & I may be able to help.
Can't comment on the Denon, but have enjoyed several carts in the Uni including:
Grace F9e, same as your latest post. This was the dealer's favorite as well. I still have a brand new one unopened just in case :-)
Dynavector 23KR - I loved it in my second system, but the Dyna cart may not be the best match for a unipivot arm, since when you lunch the stylus it's game over, no replacement. Maybe better to use a gimbaled arm with the Dyna.
Sumiko Blue Pt. No.2 - also works fine.
Franks makes some good points re: the compliance, etc. Like all here, it all seems to come down to the sum of the parts. The following links may be useful in your search:
http://www.cartridgedb.com - has both a tonearm database and a cartridge database. Just enter the cartridge or arm model & you will get all the data you want.
http://www.vinylengine.com - also has a tonearm database & other tidbits.
There are also several Oracle tune up URL's out there if you decide to go for good looks & sound over plain Jane reliability, good sound & ease of use like the Regas.
Hope that helps.