Hi cgturner7
You will be happy with the 7mm-08 its a good sensible calibre & is a great choice for your son
Dont no much about the encore but have used a tikka before & would have no hesitation reccomending it to you,Tikka are good quality,accurate & would be an excellent choice for your boy.

Just a personal thing but I definately prefer to have spare rounds in the magazine instead of fumbling around & loading another round just in case a follow up shot is needed & I would never consider bying a single shot rifle as a hunting rifle.

Hope this has been some help to you