Yeah, a-c measurement was taken with forks mounted and wheels on so 395mm is more likely to be correct. My back will probably welcome that losing that bit of stretch.
Thought you might say that about the position! The safest way to go is buy a few bits cheap on here - you can always pass them on again if it doesn't work for a minimal loss
May be worth adding a little bit of extra rise to the stem too, although I'm no fan of 'sit up and beg' it might ease the back as well. Just don't go too far else you'll lose feeling at the front and numb your bum!
There is always planB too - the revered* Flexstem!
Retro forks will do a job and you'll notice the difference (I really liked my old RC35's) but modern forks knock the socks off older ones. As others have said you won't go far wrong with any Fox or RS Rebas/Sids. Also consider Pace RC39's if you can find a decent set. If you go modern get the newest and best you can afford.