Most of the aftermarket barrels are geared towards accuracy--which means they expect the majority of customers to be using quality glass.
In other words, its gunna be tough to find a good aftermarket barrel that is read to accept iron sights.
However, if you feel like updating your current sights there are a few options...williams fire-sights, tech-sightes, etc. Look around and see what he likes.
If you are ready and willing to drill/tap or have dovetails cut, then mounting virtually ANY iron sights will be possible. As you mentioned, it is important to find a competent and trustworthy 'smith.