recommendation for a high end analog system

Late to the party here, and I agree with the general thrust that your table is capable of delivering far better results than you're getting out of it with the arm and cartridge you presently have.  The 103 is a good cartridge, but not a great one and the Sumiko arm is in the same class.  Your friend's arm and cart are truly major league.  

Further, @mijostyn and @bkeske are correct.  I have a 1984 Sapphire purchased new off the dealer floor and have found it to be a very easy table to work on that is superbly reliable.  I did have it updated by Sota about 10 years ago with a Series V platter, new springs and composite armboard to fit a Graham Phantom.  I'd looked at the TriPlanar and even spoke to Tri Ma about a Series III he'd posted here.  I'd also considered SME, Reed, Kuzma, JMW and even attempted a rebuild of my original Magnepan Unitrac 1 that didn't work out.  For my needs, the Graham was the best compromise.  I'd sold SME for a few years and really liked them, but strongly preferred VTA on-the-fly.  The JMW and TriPlanar wouldn't fit without modification, and I frankly felt the JMW was not made to a standard I found acceptable.  The 9" sized Graham, SME, Reed and Kuzma are all essentially drop-in replacements if you purchase a new armboard from Sota for the tonearm you choose.  Sota can guide you very effectively there and they've been doing it for a long time.

For a cartridge, there are dozens of higher performance choices that a better arm can really take advantage of.  I personally have a preference for Dynavector, and have also experienced stellar results with Ortofon, Koetsu and Lyra.

Because there are so many alternatives, the best thing you can do is be patient and research what's available.  Once you feel comfortable with your knowledge base, pick a budget and build in a bit of wiggle room. World-class arms can often be had for ~$2K second-hand and half that for a brand-new superior cartridge.  As some have mentioned, you can also look into a more capable pre if you wish.  No matter what you do, just remember that you are into this to please yourself and time is your friend in that quest.  Keep that in mind and you'll do fine.

Happy listening! 

@effischer 

Which Graham tonearm did you get? Phantom is quite expensive.
How about the cartridge?

Surprised that a Reed will fit and not a Triplanar, since the Reed is basically a copy of the TP, in terms of the VTA adjuster which affects the arm geometry as regards mounting.  Unless you refer to a 10.5-inch Reed.  Don't know whether Tri can supply a 10.5-inch option for the TP, but its worth asking if the OP wants to spend that much. The Technics SP10 turntables, with their square, raised escutcheon surrounding the platter, is also a problem for my standard 9-inch TP, but no problem for my 10.5-inch Reed.  I vote again for the Eclipse motor and motor controller/speed control upgrade, for what it's worth.

Triplanar will fit on a Sota Sapphire -
https://www.stereophile.com/tonearms/the_tri-planar_tonearm/index.html

Also no problem Cosmos or Millennia either.
In the old days Wheaton used to supply precut armboards for Sota’s..

All you need to do is order a blank armboard. mark it up and get a machine shop to cut it for you if you cant do it yourself.

At the time I purchased my Graham, it was a great deal less costly than they are now.  I'm not sure I'd go that way now given the now-doubled investment.

I'd started with the DV 17D3, having moved up from an antique 23RS MR that was originally on my Magnepan.  It was not a good match with the Graham (too light), so went with a XX2 MK II and have been very happy with it.

@lewm @dover 

When I went through this project 10+ years ago, I'd contacted Kirk at Sota to get some advice before I started narrowing down my choices.  He'd mentioned that the TriPlanar was rather tricky to set up on the Sota and that the Reed was a more forgiving design in that respect. 

Because I live in a rural area with limited audition and inspection opportunities, I took him at his word. Tricky set-up didn't bother me, but my installation requires pretty much a once-and-done to be useful.  Pulling the table out and adjusting was not desirable.  So I shelved the TriPlanar.  A personal fit as opposed to a mechanical fit.  My time last evening was limited and I did not communicate that well.  Apologies.

I decided to stick with 9" arms and found that a 9" Reed was a unicorn at the time.  No one had one that I could find, new or used.  I didn't like the nearest retailer for the Kuzma, so leveraged an old contact for a Graham.  The table had already been upgraded, so I called Kirk again and had him make up a pre-balanced hybrid aluminum / composite armboard for it.  After some very minor adjustment to get things just so, the Graham fit perfectly and has maintained that fit ever since.  I kept my old bucket of Sota balance shot for nostalgia's sake.

Hope this clears things up.