if you have the LT bag supports on there now then drill new holes and bolt them right onto those supports !!!
that is what some others here have done with their hardbags.
VN 900 custom "Cheapo-Glide"
Reckless (clone of) fairing
Sony dsx-s100 stereo
Pioneer (for now) 6X9 2-way speakers
Mustang "daytripper" seat
Rear lowered 2"
Cobra powerpro HP 2-1
Homemade intake with K&N filter