Sounds like a tall order with all of your dislikes. There seem to be very few stainless hinged 6.5 creedmoor rifles out there to choose from.
Why not let them pick & if it has a magazine have them replace the magazines if they get lost or damaged. Most rifles these day's are all magazine fed, not many hinged stainless rifles out there. Not sure how old your son's are but I'm sure they already have their eye's on a rifle they both like more than what you have in mind.
Or you could always buy a used or other new blued gun and have it cerakoted like previously mentioned. I'm sure they'd like the coated rifles more since they can pick out the color.
My two son's are way off from going hunting yet, but I ended up putting together a Savage Lightweight Hunter in 243 & paired it with a Lady stock since it has the shorter length & higher comb on the stock. The Savage Lady was purchased in 223 so they will practice with that barreled action before moving up to the 243.
After that I may end up letting them choose what they want for themselves. If it's going to be a hunting rifle they will keep a long time, might as well be something they like more than what you like.