Was thinking about getting one from Mitchells. This will be my first bolt gun. Is ammo for this( non-corrosive, 8mm surplus) available for this weapon at low prices? How would it do with a scope? Am I better off getting a 1903 from CMP instead?
I would suggest that you get a Russian Capture or Yugo Capture KAR98k for around $200. You'll be getting a rifle that the Russians pieced from original German K98's and you'll pay less for it, than you will for an overpriced M48 with no history from Mitchells. Here's an RC K98 I received from SOG. AIM probably is the best place to get one though IMO.
Keep in mind an M48 is not a German K98 and they are not interchangeable. THe K98 is a large ring full sized action and the M48 is an intermediate action rifle built by the Yugoslavs. The M48 came about after WW 2 and is only a copy of the K98. Overall the action on the M48 is approximately 1/8" shorter too.
Here's my Yugo M48 that I got from Century for only $70. The bolt does not match the rest of the rifle but it's still a nice shooter and everything else is matching.