Falcon 2000EX or LX EASy II might be what you like. Cruise at M0.83 (effectively) and you can squeeze out just over 7 hours of flying time. If you reduce to M0.80 or long range cruise, 9 hours are possible (I did that already). Not sure if you can do SCEL-KMIA in one go, the LX might do it.
Globals are quite expensive in maintenance, from what I could gather. All planes are expensive, but the Global seems to be in a higher category. Probably a second hand BBJ might even be cheaper!? I would not rule it out.