Longshot gave you the Cadillac option, I'll give you the Buick option....
Start with a Remington SPS. They come in various 7mm and 30 caliber magnums.
1. Choose a good scope and mounts.
Take the rifle out and shoot it. If it shoots, great. If not, continue working.
2. Float the barrel and get a decent stock like HS Precision or Bell and Carlson.
3. Trigger Job - have the factory trigger tuned to somewhere between 2 and 3 pounds.
Shoot the rifle. If it'll shoot, great. If not, continue working....
4. Send the rifle off to a good smith and have a custom barrel installed and have the action trued up. I chose Hart Rifle Barrels in New York (
Hart Rifle Barrels). They turn their own barrels, chamber, install and true your action for a reasonable price.
Shoot the rifle. It'll shoot now.
Costs:
Rifle: $500
Scope and Mounts: $500+
Stock: $150 - $300
Trigger Job: $65
Barrel and action job: $600
Total ~ $1900