Hello and welcome!
Glad to see another AMG owner ready and exited to mod his car.
As far as wheels go. Go with a name brand and make sure the 5alignment pin holes match the factory tool!
When it comes to the engine Mod's, My experience with ANY car is that it is best to stick with one company and go with then; i.e. Renntech tuning and etc... My recommendation would be to NOT flip flop and mish mash.
along with the above, As you will and have seen, here on the Forums you will get one of each response imaginable, mine being one...
Go Luck and Happy Driving
It you have any other questions, do not hesitate to ask,
-Dieter-H. K.-
HGmotorsports