Both great cartridge choices for a youth!

If you want a 7mm-08 I would not get a tikka, I would get a rifle built on a short action, not a long action made to shoot a short action cartridge, but in a .25-06 in a tikka I'd have no problems, I've heard mixed reviews about tikka. Many will say the .25-06 needs a 24" barrel, also something to consider. A 7mm-08 with 22" would be fine IMO however.

There are so many options and quality affordable rifles out there nowadays.

You may even consider a .270win, or .270wsm, if you go with the wsm I'd make sure it was built on a short action like the 7mm-08, otherwise just get a .270win.