Depends......
I started again (after a 20 year hiatus) with a 750 Honda Nighthawk (I know, not a cruiser, but hear me out). It was a great bike to relearn riding; it did NOT get sassy with my 250# frame, and could be coaxed to about 95MPH.
The Nighthawk was a reworked newer CB750 in-line 4. It probably made in the 60-70 HP range. The bigger Japanese cruisers make about 100 HP max American Iron makes a little better than half of that unless you spend BIG BUCKS on the engine, and then they will still have a hard time over about 85 or 90 mph.
If all he is going to do is toodle around town, not get on the freeways, and is not "big boned":rofl: a smaller twin would do ok. If he wants more, he needs more engine, but the price with the cruisers is MORE weight, which can make the bike harder to handle at slow speeds and in parking lots, or pickup if it falls. It depends on what type of riding he wants to do, and his riding skills.
I have since moved on from the Nighthawk, and now have 2, a Honda ST1300, V4,sporttourer (making 115 RWHP) and a Kawasaki ZX-14 Ninja in-line 4, (making 170 RWHP) which I call an "old Man's" crotch rocket. Different kinds of bikes for different types of riding.
Hope this helps, Ride Safe...