Well, there are two options; either wait for the tuner/RDS on the empeg (which, although much better in terms of reception than the mk1 tuner, won't necessarily compete with the best from Sony, Blaupunkt, etc - after all, they have large teams of people who just design tuners & write RDS code) or use a 2-head unit system using the Sony/whatever head unit as the amp for the empeg.

That way, you get full tuner/RDS service without any issues, plus empeg. The TA will interrupt the "aux" input on the Sony & Panasonic models I've tried.

Hugo