[Imaginos]

I would say start him on stock so he has a working base to learn from - if he cares to. Not to mention it will match the printed manual and Sprint (or whatever carrier) can prrovide assistance for him.

Throwing him into the custom rom mix from the beginning when he has no experience might be a frustrating time for him. Not to mention you'll end up having to be his constant support tech.

Just my $0.02