I've had the SRT for 2+ yrs now as my DD. The only time I don't drive it is when there's salt or snow on the ground. I have an explorer for those days. Averaging about 13k miles per yr. No problems outside of routine maintence, oil change, tires, etc. Love the AMG engine.

Mechanical parts shouldn't be a problem since the Xfire is built on the MB R170 platform (CLK, SLKs)
Body parts for the NA shouldn't be too difficult as long as you don't mind used parts since they sold 70k cars. Body parts specific to the SRT may/can be a problem since so few were sold, under 3k cars.

If you're willing to spend $13k, you can get a lower milage (50k miles) SRT6. See link

Used Chrysler Crossfire SRT-6 For Sale Gainesville, VA - CarGurus

good luck