I would say 50 hours is being very generous. Maybe the first time it will take a while, with testing and making needed changes, but once you have one working it is very easy to duplicate. I use a bare bones Windows 7 Image using ImageX, and I copy/inject drivers using HII. I then install our standard apps using a batch file that in return calls all of the installs I require. I find that kicking off a batch file for our standard apps works easier for me, as for some reason my distribution packages frequently fail in Provisioning. Not sure why, but some day I'll figure it out. One nice thing is that with installing apps from a batch file instead of dist package is that when I need to update something I just change the batch file, and don't have to change the Provisioning task.
I have a task for each location as well. I am unable to reliably count on the Preferred Server. I just use a Template Variable for the server names. I also pass this server name to the batch file as a command line switch.
50 hours should be more than enough. Since LANDesk is already in the environment you probably have your applications packaged already. I spent a couple months packaging everything for us a couple years ago, but that's mainly because a lot of our applications have customized installs and it took a long time to test and get everything to install right. Now that everything is packaged separately I can swap in new or updated versions of applications fairly easily, then just run the gold template again to create the locked copy everyone else uses.
I also update the core image once a year to install all the patches from the previous year. Cuts down on the time it takes for the patching component to run (shaved off 20 minutes a couple weeks ago).