Okay so I couldn't find the exact GTX style wm6.5 theme so I made it myself for the HD2 to go with GTX sense theme and the stock TMO HD2 rom.
I use these taskbar icons...
http://forum.xda-developers.com/showthread.php?t=520547
...And here is a link to the GTX sense theme which is very easy to install on our HD2's...MAKE SURE to use the NON COMPRESSED version, CFC compressed doesn't work and we don't need it because our phones have tons of space and speed and don't need compressed images.
http://forum.xda-developers.com/showthread.php?t=592584
AFTER you install the GTX Sense theme...
Step 1.) Install attached Cab (note: this will change the top and bottom task bar on whatever windows theme you currently have running, and it is fully uninstallable)
Step 2.) Copy manila file into windows folder (this is so the Sense wallpaper is in proportion)
enjoy...
Note: THIS IS FOR WVGA PHONES ONLY