Whaddya mean "old" LT? I have a '99 model and am quite proud of it. At least I was, until I learned it was old. Sniff.
There are tons of options. I have mine on a BMR shelf; I like the high mounting position and other benefits of the shelf that have been discussed lots of times. Other high mount options are the RCU shelf, the original BMW Navigator mount that replaces the map light, and some home-made cowl mounting methods I've seen pictured on this site.
Seems like I saw some RAM mounts for the area near the radio display, but that's too low for me so I've not paid much attention to those.
There are a couple of options for handlebar mounts. The one I've seen the most is the RAM mount that replaces the clutch or brake reservoir covers. Seems like I saw a bar mount beside the radio remote control; I bet you could trim the handlebar cover and make that work.
Someone on this list posted a suggestion recently that was very interesting. They said one of the (bar?) mounts included with the Zumo had screw positions that matched the distance between the screws on the clutch reservoir. All you had to do was buy two longer screws, and just attach the RAM mount to the top of the reservoir. A low-buck solution for sure.
If you have not done so already, check out www.zumoforums.com
for lots of helpful info. There's a thread dealing with mounting options, might give you some additional options to consider.