2 of my buddies have the Rino 130. We are going on an elk hunt together. I was considering buying 1 to be compatible with theirs. My question is, do I have to buy a Rino 130 or can it be like a 110, 120, or a 530? Do most Garmins "link" to each other or can they only work together if they are the same model? I'm clueless to GPS units. Thanks.