But he has gone passed the Beginner stage, and he owns two 2-strokes already.

An engine has two methods of tuning - a high and low end needle valve.

A 2-stroke has them and a 4-stroke has them. So why would one be more difficult than the other???

The only maintanance difference is that sometimes (But rarely) a 4-stroke needs to have the rocker arms adjusted. This is a simple matter of removing 2 screws, checking to see if it even NEEDS to be done (I have only had to do it once in over 20 years of running 4-strokes), and turning a screw.

He WANTS to get a 4-stroke, don't talk him out of it because YOU guys prefer 2-strokes.

boos boy, get a 4-stroke. I can't recommend one over the other (Of the 2 you mentioned) because I have no experience with either. But in general, I'll give up my 4-strokes when they pry my cold, dead hand from around it.