Hi Alikhan. I'm not sure what you mean when you say a SPR Evo. The SPR , Evo II , Evo III are seperate models per say. If you mean SPR or Evo, the Evo II and III models are fairly easy to find, although I think you would struggle to get a new model of either version now as they have been out of production for some time.
Re the SPR, they do occassionaly appear in the small ads, a new one is a very rare beast in the UK now. You could try the importers Three Cross motorcycles in Dorset. Good luck with your search and welcome to mvagusta.net. BTW for info on the different models, check out JamesC's blogspot
I just checked 3x's website, they have a 750 SR in stock. The SR is a limited run 750 F4 with the SPR engine.