Seeking arm suggestions for a Grace F9R

Thanks for all the responses everyone.  To answer all your questions: I'll look into the Magnepan Untrac rodman, thanks for the suggestion.  Yogiboy, I am using as light a headshell as I have at just under 7 gr., the stock Lustre is 11gr. I bought an 8 gr. ADC like no-brand magnesium one and 220 sanded just over a gr. off of it's top. I thankfully don't have any warped records so that hasn't been an issue.  I've also set the arms VTF dial at zero and used just the counterweight to apply the VTF hoping to reduce a little more arm mass. Dgareetson is correct, the Soundsmith ruby stylus I have is their production product, not a re-tip or re-build of an original Grace. I have the VTF set at 1.3 gr as called for on it's box, not 1.8 gr. as you suggested.  Should I try increasing it a half gram?  Do you think the F9 would mate well with an EPA-100?  I'll give the Micro Seiki's another look also.  Lewn, I determined the resonance figure by watching 2 test record sweeps, so it's hard to be more specific than "in the 7's", but I'd say more low to mid 7's.  It's stand is on a poured slab floor so I don't have footfalls in this range to worry about. So you think in changing arms trying to get to the desired 10 hz resonance I could be chasing specs rather than really achieving better sound?  I don't think I have 'golden ears' but to me it's sounding quite nice with only about 25-30 hours so far. 

The range of acceptable resonant frequency is generally taken to be 8 to 12 Hz, not 10 Hz on the nose.  We'd be going even more nuts, if we sought an exact 10 Hz.  At 7 Hz, I repeat, do you have a perceptible problem? Speaking of footfalls, if you know anyone who tap dances at 7 Hz (that's "cycles per second"), he ought to be in a Broadway show.  The only way you'll hear an improvement, if you change tonearms to achieve 10Hz (or the acceptable range of 8 to 12 Hz), is if the new tonearm is simply superior to what you are using now.  

So, if you are estimating RF with a test LP, then you have an equation with two unknowns (Compliance and Effective Mass, but maybe not, if SS gave you a figure for compliance).  Assuming C and M are not exactly known, how are you going to calculate exactly what Effective Mass will move the RF up to 10 Hz?  Like I said, it ain't worth the trouble.  Also, because RF is inversely proportional to the square root of the product of C times M, it may require a very light tonearm to move RF from 7 to 10 Hz.  It's "LewM", by the way.

Sorry for mis-spelling your name LewM, it was a typing error.
Soundsmith did not provide a compliance figure. When I said 10, I was just picking the middle of the 8-12 desired range, not necessarily hoping to find a combo to get to it specifically.  Since I'm not hearing anything displeasing I think I'll leave it be for now and just enjoy it some more.
Thanks for helping me reach this conclusion.  And a superior arm to a significant degree is not in my budget at the moment.

This is how it looks with SoundSmith brand new stylus assembly.
*price list: https://www.sound-smith.com/parts/grace-f9-replacement-stylus

This is the Grace F-9F with nude Shibata stylus (RS-9F first generation rounded shape). It my old picture, not i have second generation of the FR-9U Level II styli (Line Contact).

here is a picture from the internet of the secong generation grace Ruby stylus (not rounded shape as the first generation). But the stylus is on ALL original Ruby is Elliptical: http://photos.imageevent.com/puma_cat/fujif31andf20photos/Grace-2.jpg