Hi Horacio,
Sorry, I missed this... Firstly, by an S2, do you mean a Fidelity Research S2 headshell? And if so, in what way are you struggling to get it to work?
Secondly, are you able to get high-mass headshells to balance out on your 3009, without the use of a heavier counterweight? If so, then for me there's nothing wrong with your 3009, for use with your Denon. If not, that's a different matter...
But I wouldn't get rid of the arm, as SME 3009s and 3012s work very well on Garrard 401s. Instead, I'd be getting Speedy Steve here to make you a custom counterweight for your 3009, which is able to balance out a high-mass headshell, such as those you've ordered, and that would be a great combo. See here (he makes all sorts of beautifully finished counterweights): https://theartofsound.net/forum/show...474#post123474
FR-64s are superb arms, but I'm not sure they'd match best with a 401, as both tend to exhibit a bass-driven sonic signature, as indeed is emulated by the 103, so you could end up over-egging the pudding. In that respect, synergy is usually best achieved with complimenting contrasts, and so a bassy, 'weighty sounding' T/T would be paired with a lighter sounding, more detailed arm, etc, which is why unipivots, such as Hadcocks, can work really well on 401s, but unfortunately 103s don't work well on Hadcocks...
So.... I'd save your money by keeping your existing arm (but getting it to work optimally with a heavier headshell), or if you're going to change it, then go for a 3012. However, with a 3012 (as it's higher-mass anyway, given its longer effective length), you don't need to fit it with such a heavy headshell; indeed you can end up overdoing the mass! Therefore, if you're fitting a 103 to a 3012, a 10-12g [good quality, well-constructed] headshell would be plenty.
Hope that helps!
ATB,
Marco.