Best MMU for an Ender 3 KE?

I bought an ender 3 ke a few months ago and I've completely fallen in love. My only gripe is that I'd like to be able to print multi-colour prints as I'm looking at running a 3d printing side hustle while I still live with my parents while I can pursue learning game development (unsolicited advice for this is not appreciated, these are my choices).

I'm aware of the ercf and that is wayy too heavy a project for me. The box turtle looks promising but is pretty pricey for a kit (no printed parts, ships in march and its £280), I've just found out about the trad rack and that looks pretty good.

I want 4 lanes exactly, I don't have a lot of room so this is about the limit whilst still having storage space in my room. I'm happy printing parts for a kit but the lower the price as less complex the better. I'd rather not hard mod my printer if I could avoid it because I want to attempt not to void the warranty if possible. I'm using orcaslicer if that affects anything as well

I'm in the UK so also no kits or anything that are only available in the UK.

Any advice is appreciated, any advice explained like I'm 5 is greatly appreciated lol