The stock switch that is closest to your requirements is MX White (not MX Clear)
It is a variation of MX Blue but comes with a softer click.
It is also unfortunate to tell you that it is a rare switch, but it could probably be because I didn't personally source for that switch before.
Other alternative is to lube the MX Blue switch, it should make the clickiness and tactile a bit softer (depending on what lube and how you lube, there's a chance that you might not get any clicky sound at all)
MX Brown doesn't have any clicky sound at all. It's a light weight, light tactile switch.
When you say some mkb can be modified, what sort of modification are you looking at?
As of now, I'm not sure if there's any keyboard that fits your requirements, but my first initial thought was CM QuickFire Rapid-i (I think there's only Brown switch available in Malaysia stock, but I may be mistaken)
It has a pretty nice design, white LED, Brown switch and cost RM399, which is under RM500.
The only thing is that it doesn't have any metal finish and it doesn't have numpad (not sure if you are particular about numpad or not since you didn't mention them)
Your other option is Ducky Shine series, but it is a little bit pricier and they have fullsize keyboard.
Another option is to get a fully customised keyboard, but expect the price to go beyond RM600 for a custom keyboard that has the switch and body finish according to your specifications, and that cost is most likely not included the cost for keycaps yet.
he did mention full size thats why i recommend ducky and Cm storm Rapid - I price drop to rm330 online and some retailer unless you buy from retail shop like heavyarm still cost rm380 and there is brown switch i seen them before