I can't emphasize enough: a lot of places don't carry anything but the green stuff. And you should not mix coolants. So, if you need some coolant when off in the boonies somewhere, what do you do if you're running some non-standard coolant?
As much as possible, I like to stay with standard parts and supplies (even if they are not standard for this particular car, like my fan relays, which are from a C4). The easier it is to get parts, the easier your life will be if you ever have trouble. Not that everything has to be stock, but I try to keep the the things that are most likely to need replacing (consumables, like fluids, belts, critical electrical parts, etc.) in the "easily obtainable" category.
Joe