r/s interface on 99 caddy seville

I'm going to do a remote start/keyless/trunk release on a 1999 Cadillac Seville (STS I believe).  What interface module do you veteran installers recommend on this vehicle?  I have been out of the remote start game since 2006, and back then I would have used a 555u DEI module, buried a key, and ran wires into the door for lock/unlock/factory disarm, drivers door trigger, etc, but I know that interface modules have really changed a lot over the past 2-3 years and may take care of some of the things that use to require running wire into the door(s).  If possible, I would prefer not to have to purchase the flash module and would like one that would interface at the data wire at the OBD2 plug (similar to the 1700g if such a ting still exists).  Any suggestions would be greatly appreciated.

iDatalink ADS-DL does transponder bypass and all convenience features as well.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

thanks