Many prayers are with you- family is home from 3 years in Japan- heading to Vegas tomorrow.
I use the flat rate box from the post office- don't need to worry about weight limit. My daughter always said I could pack more in that box than anyone she knew. She swore it expanded to double the size when they opened it. :)
I sent the local newspaper- it's really "redneck" and they loved it. Lots of pics of first day deer hunting and turkey trophies and the neighborhood happenings. Sent local foods that would travel well, poured wintergreen lifesavers in to fill up voids and they loved the smell when they opened the box.
Ask your son what they don't have readily available and take it from there.