ar style sights for winchester 1300

[pythonfan]

Thank you in advance for insight. I have a winchester 1300 home defender. It has the standard ball like small sight. I want to put an ar style sight on it like the fn sights I see on some new rifle. I'm not sure where to find them aftermarket. Can I attach them to existing barrel or do I have to get new barrel? I hope I'm clearly explaining my wants.

[migz]

http://www.brownells.com/.aspx/pid=12591/Product/SHOTGUN-COMBAT-SIGHTS

tritium, expensive, needs drilling and tapping