As payasam said ... first get a 35/2.0 (Summicron-M), later add a 90mm (Elmarit-M 90/2.8, Tele-Elmarit 90/2.8, or Summicron-M 90/2.0) and you are done.

(A cheap, small lightmeter could be helpful, too !)
Welcome to the M2 club ! ... and post some photos !!
Cheers,
Gabor