from hakushin guitar equimentsfx but he live in japan, and probably gonna hard to ask him to mod, but you can buy it from mercari or any japanese proxy website
Patch cables are probably custom made, so no point searching for those (if you want to make your own just buy quality bulk patch cable in the color you want and some 6.35mm plugs) LS-2 Mods are made by a mod shop in japan that is currently on indefinite hiatus. You can try to searched for used ones or try to find WAXX mods (the ones TK uses). Or you could just buy stock, NEW revision LS-2s. AFAIK the mod basically replaces low quality components like capacitors and stops some of the frequency loss that the unmodded ones have, but the new (i think 2020 and newer) SMD LS-2s no longer really have this problem, so you will likely notice almost no difference between the mod and the stock version.