This is from my personal experience so your case might be different. But this is what I find through my trial and error.
- Between silence and no silence, I do like silence better because it tightens the switches and reduce the wobble. Making the keyboard feel more refined.
- Between variable, 45g and 55g, I like 45g the best (I also like MX Red and Brown). 55g start to feel a bit tiring for me.
- Opinion on Hypersphere ring and KBDFans rings. Hypersphere rings dampen REALLY well but it also reduce travel a lot which affect tactility, KBDFans rings sort of does everything "okay" it doesn't reduce travel much and doesn't dampen that much either. I would recommend buying official silent models.
- Have not try lubing so can't comment on that.
- Layout is heavily based on personal preference. I like standard layout for muscle memory also I use number pad a lot, so full size is best for me.
So based from your top 2 options, Leopold never made silent version and probably still won't. If you want silent your best bet is 87U Silent.
Realforce R2 just came out in Japan so I'd recommend wait for the tenkeyless version, which will come out some point in 2018.
https://pc.watch.impress.co.jp/docs/news/1081484.html