Lost key fob and remote start
 

I lost 1 of my key fobs and want to replace it. I see here how it's fairly simple to get 1 and program it myself. The question is will the remote start work by reprograming the old and new key fobs together? On another issue with remote start, the truck will only run for 10 minutes or so and I want it to run about 30 minutes. I have no idea how to set the run time or who is the manufacturer the remote start. It's not listed on vehicle options, so I'm assuming it's an aftermarket set up on my 2000 Sierra 1500. Any help would be appeciated.