Hop onto the Nightforce IG page for a live Q&A about the new NX8 F2 if you have any questions about the line up.
https://www.instagram.com/nightforce_optics/
If you search Craigslist for "lockers" the guy comes up. He's a liquidator and has a huge warehouse near Stone Mountain. Sorry, gotta jump on a conference call or Id look it up. He has all sizes. These were $300
They use an 11mm dovetail groove on the top of the receiver. You can use a pic rail adaptor, but then you have additional tolerance stacking. Not to say that they still won't shoot incredibly well...they sure do, but it's just something to consider.
Not rilly. Plenty of folks prefer the 455.
Have you looked at the Tikka T1x? It also has a built in pic rail so you don't have to monkey around with the weird euro grooved receiver.