Easy to operate (and I would say 10 cigarettes, while not being no cigarettes is kind of on the lower side.
I would recommend an Innoken T-series (T-18, 20 or 22) but I am a bit biased when it comes to pods. Unless he wants to purchase pods it either gets complicated refilling and/or other issues come into play. There is very little variation quite often (pods are getting more complicated and adjustable but to use those types of pods, well, your dad is going to have a learning curve). I've seen many folks do well with that type of mod honestly, and it's overall less expensive (he will need to learn how to fill a tank and change a coil, not incredibly difficult, but if you think it would be hard for him, I'd guess a pod mod would be best). Something that he just charges, and when the pods are empty he chucks them. That does limit juice options to whatever the podmaker "releases" and some of them can be quite high nicotine, although many have a few different levels.
I'm finding it hard to recommend a specific pod as I just don't use them but I'm sure you will get other excellent recommendations from folks on the plus side, with his LESS extensive smoking habit he may not need as many pods per week as a 2 ppd smoker.
Finally, is he on board with this? I will often say to family members (even though they may think it will be a lovely "surprise" or that he'll be less resistant to it, if they talk to said family member, the flip side of that is that he may have more "buy in" if he is helping select his equipment and whatnot. I would also say, if he rules the matter out of hand and has no interest when you bring it UP, he's unlikely to feel any differently (and perhaps, even MORE resistant with something "sprung" on him) whether you discuss if first or not. If he's really interested, get him involved in the buying process, and if he's not, well buy something CHEAP. Because there is every likelihood that it may wind up no less or no more than an ornament on the Christmas tree, really. I mean, perhaps it will percolate around and at some point he will try it, but well, equally so he may not, so stay on the less expensive side if you know he is not going to receive it with unembellished grace and etc.
My son did gift me ecig equipment before I quit and it helped, but my near miss with COPD really ALSO helped a great deal. The "I will guilt my mom" factor had SOME power, but I would never have picked it up unless I was to the point I was SO ILL, I really had little choice, even in my own mind.
Good luck and I hope whatever you get helps your dad!
Anna