Well, you are asking the right guy(even though you were not asking me)! I ultimately went with a mashup of 5 sets of GMK because my feeling is they really amplify the thock in a nice way. See, that is why I was saying the last thing I want to do is silence the upstroke. Simply the GMK's, no O-rings will make the upstroke much nicer IMO. I wanted to O-ring not to silence but rather to soften landing. This feels much heavier than 45g but then again it is not painful at all. I am just foregoing O-rings for now. I Achieved much of it just with the key caps. No one else is here so noise is not an issue. I swear though you could hear this 30 feet away. To me it sounds freakin' awesome.
The SA while also being less costly to consider has a thinner sound on this board. it is not as robust, full bodied and authoritative. Not a ping by any means but I do not like the SA as much. Honestly, they are close but the GMK sounds like you are doing some kind of Jujitsu tapping holes in solid wood. If noise is an issue forget this right now. It is easily louder than a Model M and certainly MX blue. It is not Hollow like that though. The little click on Blues. It is a solid sound. Like I just said my best analogy is rapping on hard wood. The stock keys are indeed quite good but not GMK. Plus you will do what, DSA? I vastly prefer the cupped Cherry molds. If you are going to do it, just do it right and say F the money.
People have insulted this board saying it is not a real Topre. BS. The President of Topre told me it was supposed to be their current Flagship board outside of JDM. He said unfortunately it was accepted to be but a novelty due to RGB. They misjudged how our group of folks thinks. Do not let that deter you if you want one. The adjustable actuation for instance is state of the art technology. You can map and program every single key independently. The plate and everything is not the same as 104UB. He told me off the record whereas the 104UB or 87U is good for 35k to 75k keystrokes they are speculating some keys on this may exceed one Million key strokes! It was better not worse. It was just not universally received. The point is, absolutely worthy of the GMK's. Just decide what you want and can get.
To get parts of 5 sets including many keys I did not need this keyboard is well over a grand to me. It is my daily driver. So I am just pointing out IMO do not let anyone tell you it is not worth the key caps. Quite frankly the stock ones are pretty darn good. I vastly prefer just the underglow. It is too bright on 1 though, I need to put a resistor. I wanted a cord but not sure what all that takes. For a board like this not to come with a braided cord was the only mistake I see. The Cup Rubber has a much nicer crush feel than 104UB because it is a different, stronger material they informed me. Indeed it is more pronounced at collapse. The reason I am mentioning this is because the Cup Rubber plus slider are what give this board a more robust sound than the 104UB. Some say it does not sound like a Topre. It doesn't in fact. It sounds all the much better. Put on the GMK's and you have a real noise maker. Nice sounds. So anyways, up to you but I explained two reasons I prefer GMK on it. Sound and feel. Plus when they get shiny with that profile it is lovely. I hope that helps! OH, btw nice Kitty!
As for Zslane, I take it you too feel Novatouch and RGB are indeed real Topre boards. It is not even like this is a cheap board. Completely stock it is amongst their most expensive offerings. Amazon is authorized to sell it for $239 but anywhere else including Elite Keyboards it must sell for $279 per Topre. I would not call this a "cheap" board in price or quality. Quite frankly it is evident that it is better quality than the 104UB IMO. Certainly worth making upgrades, but also quite competent stock. They did not skimp on the stock Key Caps by any means.