WIN98 would work nice with 512K.
On the vet side, here is the overview for the new PTSD rules and regs.
http://va.gov/PTSD_QA.pdf
Yes, unbelievable as it sounds ... the very recently touted new program is already in print.
If you have the time, take him to the nearest VA facility and sit with him and the Patient Advocate. Barring that there should be a Veterans Service Officer somewhere in your county.
Id start with the main VA number as there are a lot of understanding vets that answer the main line.
1-800-827-1000
If I can be of more help, PM me