To echo some of the more experienced members on this forum. The best equipment is going to be the one that your friend in Cambodia can receive service for. No exceptions. I would hate to suggest a brand or type of machine if there isn't a local tech that can service that machine for normal maintenance or when it malfunctions (and it will malfunction eventually!).
That being said. If your friend is in an area where service technicians may be limited. I would look for one that is as basic as possible. Less electronics, long track record, and easy to work on. If getting a used machine, ask all kinds of questions of the seller and be careful. If they don't know the history of the machine and can't give you details, stay away. Stick to the bigger names as well. Also, since you have a limited budget, I would stay away from La Marzocco and Nuova Simonelli. Both are great machines but right now people want a premium for those brands used. Look for a La Cimbali, Astoria, or La San Marco. Those brands are higher quality than say a Grindmaster, and can be found used at a reasonable price. Honestly though, $1000 is a tight budget
There is a lot more good advice on this forum concerning machines but that should get you started.
Albe