Finding a second hand rifle has nothing to do with the discussion, at least to me it doesn't. The fun part of a project like this is having a rifle built to my specs if I can't find a new version that suits my needs.
Sorrty, but that isn't in the message you originally posted. Those rifles are of current manufacture.
Does anyone CURRENTLY make a rifle in either of these calibers?
Here is a new one...
https://www.sportsmansoutdoorsupers...-action-rifles/of3/17-REMINGTON-FIREBALLRemington is not CURRENTLY making any rifles in 17 Remington. And the last link you posted clearly states it is no longer available