When I buy liquor as a gift I try to find something similar to what I know the person likes but not the same exact thing. I think it looks more thoughtful when you can say "I know you like X, so the guy at the shop said you might really enjoy this one, too."
A couple glencairn glasses would make a great gift for any whisky enthusiast. I love them.
I have one more suggestion on this topic (not to beat a dead horse, but if there's two topics I love talking about and could go on for too long, it's hockey and whisk(e)y). If your dad is into middle of the road scotches (taste-wise, not price wise; I know you mentioned he likes them peated, but still, who doesn't like a nice clean flavor), I would recommend 12yo Cardhu. It's changed my life (hyperbole, but maybe not). It retails for around $40, but it tastes as good as many things I've had at twice the price. It's not really well known, but it's available enough that they will probably have it at a high end store. Something to think about even for yourself, because if you're cash strapped and you still like drinking scotch, there isn't anything better that I've found.