Best Way for my TT to reach my Pre-Amp!?

A couple of thoughts.

You might be getting lost in the weeds a bit with all this talk about impedance matching.  The Nagaoka cartridges are MM cartridges and they should work with most any MM phono preamp.  Unless you get something really exotic, most phono preamps should work with the Marantz.  I have a Nagaoka MP-500.

I wouldn't go crazy on a phono preamp, the Marantz is going to be a limiting factor in terms of ultimate sound quality.  You can spend a few hundred (not sure what your budget is) and get better sound quality than the built in phono pre in the Marantz, but your turntable and the Marantz are only going to take you so far in terms of sound quality.  If you want to try tubes, try one of the Pro-ject offerings, or something like the Parks Puffin if you want to go solid state.  I think anything beyond that might be a waste of money for your current setup.

Let me start out by thanking the OP for starting this thread. I’m a relative noob to all this and will be adding a phono stage to a receiver(Oulaw RR2160) as well. Which I think would be the best solution for you if you just don’t lengthen the cables. I’m learning quite a bit from this thread. For the record I’m looking into mostly tube phono stages and will most likely move into a integrated amp a year from now.

For the money, it’s hard to beat the Schiit Mani and Blue Jeans LC-1 low capacitance RCA cables, and will far exceed the built-in phono stage of your receiver. Been there, doing that.

My thoughts right now is just go with a pair of extension RCA cables and see what you think.
I'm betting you will be quite happy.
I had a TT sitting in a similar fashion, it's cable was 18" too short to reach.
I made it work even more down and dirty with a pair of RCA adapter and another regular set of RCA cables.
Sounded PDG to my ears.
Of course that was just temporary and I had a longer phono cable made from the TT to reach.
But my point is before you blow a load of dough just try it.

Greg is correct in that the Marantz is going to be the limiting factor no matter how good an independent Phonostage you put between it and your TT.