Hello,
Only have some of the information you need, but thought I might post in case it is helpful.
No experience on T5545, however I am currently involved in a rollout using Wyse v10l thin clients and TCX. TCX does not require a software installation on the virtual desktops, rather a traditional windows server licensing server (like the connection manager) to parcel out available tcx licenses to thin clients as neccessary. This is how Wyse support described the process to me, I have not yet implemented it yet and am not sure if there is any config involved on the actual thin client, but wyse seems to think it works quite well.
With regards to cool new thin client solutions, I recently saw a very sleek sexy device called a Pano thin client. These boxes use a pano desktop service installed on the view image to handle usb redirection, are cheap, and are well rated. The company is also hungry for business and will probably offer agressive pricing since they are new to the scene. If you see one of these in person, you will be sold. We sold Wyse to our customer, but would have seriously considered pano otherwise,
Hope this help,
Jake