The aluminum Keychron case is not a case, it's a skin that goes over the stock case. It may alter the sound a little but it's still a plastic case.
It's also a VERY tall keyboard, if you have any RSS (carpal tunnel) you will not like that keyboard or you will require a wrist wrest. It's at the very limit of what ergonomics experts recommend.
Making your keyboard sound that way CAN happen but it takes a lot of work and you won't get it from a major brand out of the box except maybe Topre. Not that factory boards are bad, but few if any can match that because they aren't going to do the work.
You need to use either high end switches (which few manufacturers offer and doesn't always do the job) or lube them yourself, you also need to lube (and possibly) bandaid mod the stabs. An aluminum case (actual aluminum case) can help but how much is dependent on what two you compare and I still say it's secondary to lubrication and band aid modding because the lube is altering the sound at the source which is always better than trying to alter it after. It's not that the case doesn't matter but it's not required. My GMMK sounds every bit as good as my NK65, my Chinese custom and my heavily modded Filco.
As for the Magicforce (amazing little keyboard), pretty much any mechanical board can sound that way but it means desoldering the switches, desoldering is much more difficult than soldering unless you have the specialized tools for it. So what can you do? Well if you want to make a beast out of a budget keyboard Spacecat offers a bare PCB (
mf68), unfortunately it's not built, hence the price, by this I mean you obviously need to add switches but also diodes and controller (it's not as hard as you think). Pretty sure at least someone else does or did offer something similar but pre-assembled (LFK maybe), even if you find one it's going to be more expensive, probably more than double what you paid for the Magicforce. The MF68 is cheap and if you screw up odds are the controller is still salvageable and diodes are a dime a dozen so if you want to learn this is a great option. And no, you do not need a hot air station to solder this, people solder these all the time with normal solder irons, it takes a little practice but after a few you will get the hang of it. You will also want to fill the bottom with foam, foam kitchen shelf liner works well.
I understand money is an issue but this is a LOT of work and not going to save you much compared to just buying a GMMK or Keychron and lubing it up and in the meantime your board is out of action, a board that could be used as a spare or loaner rather than being ripped apart for the few bits you will re-use (the case) or worst case ruined. If you want to go down that path you may want to try and find a cheap, used Magicforce to keep yours working. Another board to consider is the Novelkeys Nk65 Entry. It's a little more but it's a good little 65% board. You also mentioned you wanted specific keys, the Nk65, MF68 and GMMK are programmable however the NK65 and MF68 take this to heart with open source firmware. Basically any of these will let you reprogram it how you want you just may have incorrect labels, this is actually pretty common on high end customs simply because we can swap what they do but caps only come in a few layouts.
By the way, do not desolder your switches and try to use them on a hot swap (Keychron, GMMK, NK65), you will need fresh switches. Trying to re-use soldered ones can damage the hot swap which are already fragile enough.
One other thing, this goes back to the money.
You can always swap caps later but switches often cost as much or more than the rest of the keyboard and require the most effort, don't go cheap here expecting to change them later, do them right the first time. If you like browns, great, get browns, don't go for some linears just because they were on sale or a friend had a spare set, unless you have hot swap and those switches are free it will only cost you more later, possibly a lot more. By the same note don't think you need something like Zeals for a good experience, high end switches are great but what often makes them so much better than normal switches is that they get lubed better, everything after that is just fine tuning. Lube is the great equalizer on keyboards.
Side note, don't forget caps. They matter.
Thin PBT is horrible and needs to be shot out into the sun where they melt 1000 deaths, Doubleshot ABS is good, thick PBT (1.3mm or thicker doubleshot or dyesub) is better, better still is thick PBT with o-rings to further dampen the sound. Most people use o-rings to dampen bottom out that is not the intent here, mine do not touch, they merely add mass to the cap to change the sound but it doesn't work on all caps that way. I use
these, it's a 139 key set so it should work with almost anything, if you use it on floating board like the GMMK or Magicforce the bottom edges are a bit sharp (you could sand them) but other than that it's a fantastic set for the money and with RGB backlighting looks fantastic.
Here's a pretty good shot of how they look. You can probably get these really cheap right out of China or in smaller/cheaper sets. I just wanted something that worked on all my boards and these fit the bill.
