Know what you're getting into...
I'll be a bit more expansive in my reply than "don't get a Robinson". However, you may come to the same conclusion.
The Robinson Helicopter is a fantastic, well-engineered, and safe machine from a mechanical standpoint.
Robinson designed a great recip (as opposed to turbine) bird and thus shaved off millions of dollars in aquisition and operating costs. So, as an owner, instead of being filthy rich, you just need to be very wealthy.
If you research the crashes of R22 and R44, it'll give you great confidence into the mechanical reliability of the machine. That's because almost ALL are pilot-induced. But you end up just as dead.
I assume that your dad has money, so cost is not an issue. But the R44 has a safety problem due to the niche market of low-time, rich, owner-operators who can't wait to take their friends for a helicopter ride.
Helicopters are serious machines for professional pilots only. That is my opinion. If your dad has that approach toward flying, then get one.
But if he is like most amateur pilots, with lots of other things going on in his life, a high-powered job, used to fixing things with money rather than brains, wanting to impress people, then an R44 is a death-trap. With 4 seats.
As a pilot of both fixed- and rotary-wing machines, I have paid for my experience with little (and not-so-little) mistakes along the way. Fortunately, none have killed me. But due to the unforgiving nature of helicopters, as well as to the necessarily long process of becoming a proficient pilot, I believe many more "beginners errors" have serious consequences in a chopper. Some goofs I did in a plane would have been much more serious in a heli.
And thus a helicopter is not the place to start as a pilot.