this is the link to the Download page for your phone:
http://www.htc.com/www/supportdownloadlist.aspx?p_id=13&act=sd&cat=all
this is the the wm 6.1 page. just put your serial number and answer the two questions.
sorry if you've already got this far, or been tried it already.
http://www.htc.com/www/SupportDownload.aspx?p_id=13&cat=2&dl_id=21
lemme know if this helps.
BTW i have the HTC Touch for Alltel, so i've been through the same thing. GL
The problem the OP faced was that the upgrade wasn't available for his/her device. Most likely a carrier issue.
Aside from that, the one you're linking to is a generic upgrade option, which will erase all carrier customizations. The carrier specific customizations are generally built into the ROM.
The TyTN II is GSM, so not having customizations may or may not disable the phone from working properly on his/her carrier, but generally speaking, data and messaging won't work without customizations.
This leads me to xda-developers.com, where the OP can find a carrier specific ROM for his/her phone, which will include the customizations.. whether it be a carrier specific official ROM, or a 3rd party ROM that requires the phone to be unlocked.
I have the Vogue (CDMA Touch) and Mogul (Titan), and have used both official and 3rd party methods. The TyTN II and Titan are sister models, and the Vogue is an upgraded, smaller form factor of the Titan (less a few features, e.g: Wifi). So, the upgrade process for the TyTN II should be similar to the Titan and Vogue.
-Michael