hi Gary,
On your hard drive, if you used the MPLAB IDE you should find this Folder, all the headers are there.
C:\Program Files\Microchip\MPASM Suite\Template\Code
I had a search around in my microchip folder and found all the .inc files are stored under "C:\Program Files\Microchip\MPASM Suite"
Try including that in your project build directories and see if that works.
You don't use HiTech c for assembly, you use that for writing code in c.
If you want to program in assembly follow these steps:
1) In MPLabClick on Project -> "Select Language Toolsuite"
2) in the new window, choose "Microchip MPASM Toolsuite" from "Active Toolsuite"
3) Click "ok" and try to build again