The KMCS is aight but seriously overpriced IMO. It's based on (read: Aside from a couple of additional pockets and ties) Russian suits
and, surprise! They're also sold out, or at least difficult to source. Jack Pyke, North Mountain Gear, Arcturus, Voin (another Russian leaf suit)......I have a lot of experience with ghillie suits in the UK and it's much easier to find something suitable these days than previously so........what you need to decide is how much effort you want to exert. You could buy something like an Arktis or Webtex ghillie base and add garnish.....effective (British Army snipers tend to follow this MO) but it does demand quite the investment of time. You could buy a simple "Yowie" suit from Aliexpress or eBay
- the guy who originated leaf suits in the UK swears by them and has been using them effectively for more than 20 years - experience and skill are far more important than just buying an "Invisibility suit" and assembling your own is quite the learning experience.
I never, ever wear a suit out of the box. In order to tune a suit to the British countryside I'm quite prepared to spend some hours on additional foliage, or in some cases, eschew leaf suits as a base entirely and work from scratch. If I were to wear a suit out of the box that I felt wasn't an extortionate price then........I'm genuinely not sure. Perhaps the Russian suits the KMCS is based on as they're essentially the same and a great deal cheaper.....
For late spring and summer, I have a North Mountain Gear leaf suit that I dyed to tone down the extremely vibrant colours. On top of that base, I added Haloscreen and Nanoscreen from Le Covert Sartorialist as well as a couple of pieces of ConCamo strips for contrast. Aside from foliage loops, I haven't done any extra tailoring other than to add stirrups to the trousers and a couple of fixing points for braces - I do that with all my ghillie trousers to prevent them from riding up during crawls.
Autumn/Winter, I have a suit I made myself based on an ANA sniper suit which had no foliage on initially. More Nanoscreen, some fake leaves, more ConCamo elements, and then some raffia and hessian for texture and contrast. Crawl pads in the trousers, and braces once again......works perfectly well.
Finally, in grassy terrain, I have a Viper-style hood in A-TACS FG that has a plethora of foliage loops so aside from a base of hessian and raffia, I tend to rely more heavily on natural foliage and add it on the day. FWIW I was always taught a suit should be at least 60:40, natural: artificial so that's a rule I stick by.