Just to chime in with my 2 cents. I think SWFA has the TPS rings and I have used them exclusively on all my rifles since I found them. Won't have to worry about lapping these as every one I've got has been perfect!
I wrote two articles on the Black Rifles for this web site. In the first I made an observation you might want to remember. It went something like this: you can't put a cheap scope in good rings, nor put a good scope in cheap rings and expect either to give your rifle it's full potential in accuracy. When you go long, tiny things show up BIG! I believe you have a fine rifle at a very good price. You saved a lot of green so I will advise you to use the savings on quality rings and a good scope and get a bubble level. Also, a 20 MOA rail is a big help in reaching way out there with a 308, especially with a scope that has little come-ups.
Personally, and I'm 74, I don't think you should be fixated on FFP. I shoot long with a SFP scope and see no problems. Others will disagree, but you (I think) and I are not into the competition long range shooting so any advantage of the FFP scopes will not outweigh the cost.
Also, fine used scopes can be found at a fraction of a new one. I've bought many on this site myself. Rarely are they abused and you can check out the seller. Even though I don't shoot LR competitively, I still do love hitting what I'm aiming to hit!
Lastly, spending a little more now will save you $$ later. If you buy cheap(not inexpensive) parts now, later you will want better and have to pay again. It will also make shooting with quality parts way more enjoyable! Isn't that what you want?