I figured I should chime in here, since I've just used e-cigs to quit a 10+ year smoking habit. In the 4-5 months since I bought my first e-cig I've gotten a few people to try them out, with mixed results. The problem some folks have is that it's not exactly like a regular(analog) cigarette. The differences, to me at least, make e-cigs better than analogs in almost all respects. If you want to quit they make it much, much easier. If you don't have any desire to quit though, then nothing can exactly replicate the flavor, feel, and satisfaction of an analog.
I have had luck convincing some skeptics though, so I wouldn't want to discourage you from trying. I would suggest, as others have already said, a cigarette-like kit; I started with a 510 kit. I would also recommend having a few different flavors. I wanted to recreate my
tobacco flavor to start, but quickly moved on to more interesting flavors. Your dad might try it only if it's close to his analog smoking experience, but might only stay interested by sampling new flavors.