if you had a pinky pump(those evil things I will never own again) you could pump in some pinkies.

I'd work on hydration and heat for now and watch him hopefully liven up. You said he ate a week ago on his own. Maybe the hydration will inspire him to continue. Force feeding should be one of the last possible options IMHO.

I'd check on him and if he's off his basking site, maybe give more pedialyte and put him back on. Make him move off of it himself.(forcing activity) If he stays under it for 20-30 minutes, you have a problem...a vet problem.(assuming you actually have a 147 degree basking site which is pretty hot for a water)