Maybe he doesn't have the skills, time, knowhow or desire to build one himself. Homebuilt ones usually don't look as nice as factory molded plastic too.
As far as I know there is no third party wired sensor bar, just the wireless ones. Can you set up the wireless bar closer to your seating position? Seems like you have an awfully large space between you and the sensor bar anyway... Must be a pretty kickass home entertainment system.