Take look at the Garmin 96/96C. It's small, has great battery life, not an issue if you use the cigar lighter cord, doesn't need any external antenna, has a really functional yoke mount. Only problem is the incomphensible operators manual, which I guess is a common complaint for all the GPSs. You can eventually figure it out. There arn't many (any?) on the used market because it's just recently been appeared on the market.
