Coolant system help

Hi again all!
So.... my radiator top hose blew up. My 1996 ja22w is on the side of the road about 3 miles away. I will take pictures next time i see her. My plan A is to buy a universal hose install it, top off fluids, limp it home, and wait for replacement parts before driving again. My wife was driving when the hose blew and she said she was going up a hill and it lost power so she pulled over. 
my questions:
does anyone know the diameter of the stock upper hose so I can grab the right size universal hose?
can anyone reccomend a site for the actual replacement parts?
Is there anything I should be cautious of when refilling coolant and limping home?
Why could my hose have blown in the first place? Was it just old or should I be concerned the same thing will happen with the new hose?
AND FINALLY, what are the odds that the engine is totally wrecked right now?

Thanks for reading! 

I don't know the hose size for Gen 2 but the engine will be ok if you shut it off as soon as the hose went.  They can just go due to age and if this is the original, it's not surprising.  The top hose usually leaks first because it gets far more heat than the bottom one.

Assuming it's like the Gen 3, you won't get any air locks as long as you fill slowly.  Ensure the heater control is turned to full hot (most cars these days don't have a heater control valve and just direct the cabin air accordingly, but it's best to be safe).

I'm hoping she pulled over as soon as it went, but she did say the engine was loosing power. I'm hoping she didn't not notice the hose and drive until it started to seize. Thanks for the reply and I will update asap

If it was losing power, that's not good.  Maybe take out the spark plugs and see how freely it turns over from the crank pulley, before trying to start it?

The temperature gauge (which is probably very non-linear anyway) wouldn't have shown a problem if the water dropped enough to uncover the sensor.  Hopefully, being the top hose, the head would have stayed full, although the coolant would have boiled in an instant.

I pedaled my butt out to the car, grabbed the blown hose and found a close enough replacement. The engine turns over freely, but I haven't tried to start it yet. On my way back to the jimny now. Pray for me!

Welp, new hose is on and coolant is re-filled. It turns over, but doesn't start. I'm on the side of the road still so I think I'm going to have to call for a tow. There is one symbol on the dash when I turn it over but I can't remember if it is usually on when the engine is being started: