I have had 3 gliders for almost 3 years now and one died not to long ago and just yesterday the brother passed of that one and now I'm left with the cage mate and don't know what to do. Should I get another? Should I re-home him? I'm at a total loss. Please help

gliders are colony animals. it is best for them to have one buddy.
if you want to have gliders, I would suggest search craigslist. most of my
gliders came from there and I had no problem with scams, just be careful.
we always handed off glider and payment at the same time at a meeting location.
look over glider first if you are worried. we also got glider very cheap or
free.
if you don't want gliders anymore you can rehome. we just looked for someone
that had experience.

How young should I look for in a glider? As the last one I have is almost 3 years old and I'm looking for a new cage mate as I don't have the heart to re-home him and want what is best for him and it has been a bit of a struggle to bond with him as he has been in a bit of a crabby mood since he is the last one, I believe that's why he may be like that. So I'm worried about the other glider as he has been crabby.

follow the introduction procedures on this site or other sites. a lone glider
has a high probability of success. As most gliders want a friend or more. We had success all the way to 10 gliders. but we downsized to 6. after awhile 2 rehomes came back, the new owner was not taking good care of them. so when I tried to make the 6 gliders into a 8 colony and the Alpha would NOT take the 2 back. he would fight them.
there is a small chance they wont go together but fight. BUT if you
FOLLOW THE PROCEDURE!! I think you will have success.
I think age is not an issue, but if you get one single that has been single for
a long time they might be more likely to reject the idea of a cagemate.
I would look for 1 that is 1 to 5 years old. or maybe get 2 already together so you will have 3. I only took neutered males. NO BABIES. and neuter cost can be expensive.