I currently have a 40 channel Uniden with a remote handset similar to the 7760NB unit. I can't comment on the above selections directly other than to say stick with Uniden/GME/Icom models. If/when I upgrade to an 80 channel, I'd probably not go with Uniden again though. Although it has performed faultlessly, there was no possible upgrade to 80 channel, unlike the other brands. So for future upgrades (which may or may not happen, depending who you talk to) I don't want to get stuck with another un-upgradable unit.
However, whatever I get will have the remote handset again. My main unit is hidden under the driver's seat, with the handset only on the dash. I went that option as there isn't a lot of mounting room in the pathy. Thus controlled by the handset, with both mike and speaker in the same. (I'm not sure if other brands have a speaker in the their handsets tho)
Antennas will depend how and where you intend to mount it. You have 'ground dependent' and 'independent'. Independent means you can mount it on the likes of a bullbar, dependent means to work well it needs to use horizontal areas such as roof or bonnet as a 'reflector plate' and should be mounted in such places. However, even ground independent antennas are affected by the vehicle body. If mounting on the bullbar for instance, the greatest signal strength will be towards the rear, due to the metal of the vehicle behind it. Likewise mounting on the rear bar, make the greater strength to the front. Personally, I've never noticed an issue on either the tracks, or the open road.
The length and type of antenna (whip, spring, fibreglass) is to your preference, but if 6.6 db, they pretty much perform the same. When I bought my antenna, it was a pack that came with a short 3db, and a longer 6db. 6db has a greater horizontal range, but they tend to be a flatter wavelength and can be blocked by hills. 3db has less distance range, but is less likely to be blocked. There is a good description somewhere - I'll try to find it. All signals can be affected by hills, buildings and the like, and is classed as a 'line-of-sight' signal.