Brabus or RENNTECH? or someone else?

[hersheylala]

IF you were to pick a high performace outfitter which would you go with and how many miles is too much to make a build not worth it? I have 01 CLK430 with 39k, a 01 ML430 supercharged and NOS with 175k (R.I.P. yesterday) and a 97 S600 with 75k. I would like to put some work into the CLK, and I am looking for suggestions. Also... Does mercedes make a manual transmission that is "plug and play" for the CLK? If not.. is it even possible?

[MTUpower]

Renntech is my choice, but I've never had the $ to make such a choice. I've been to the shop many times and the professionalism always impressed me. They are in Lark Park, FL, close to my work in winter.