The 10 yo will take a while to appreciate very much. The investment would be for your future enjoyment.
It really depends upon your palate. What do you like?
HP 12 is heathery (sometimes leathery) with some whispy smoke and stewed oranges.
Caol Ila 12 will be much stronger than the Talisker 10. Think iodine (seaweed) and a good bit of peat and peat smoke. Also, will feel oily.
It's been a long time since I've had Glen Garioch 8, 10, 12, 15.... The younger 2 were very one dimensional and for me, not very pleasant. 15 was the best of the group. Recollections are that these are much lighter with a little bit of cinnamon, some fresh wood notes, and grasses.