AC for bedroom--which model/options to get?

[David and Jo-Anna]

We have been persuaded by the very helpful discussions on this forum to get a second air conditioner for the bedroom since we will be living in our Big Sky for weeks this summer in the heat and humidity of Georgia, the Carolinas and Virginia. Now the tougher decision of which model/options to get, so I'm soliciting more excellent advice from this forum.

The first decision for me seems to be whether to go with the low profile vs. standard size unit. Looks like the height difference between the low profile Penguin and the standard size Dometic or Coleman units is around 3". How important is it to go with the low profile version? I'm putting Max Aire covers over the Fantastic Fan in the kitchen and the Fantastic Fan I'm adding to the vent next to the shower, so with the arch of the roof, I expect that these vent covers will be the high points on my rig--higher than a full size AC up forward. Am I wrong on this? And if the height differenc is not a significant issue, is there any other reason to go with a low profile unit and/or are there advantages to going with a full size unit (I seem to recall someone suggesting that the low profile units might be noisier than the full size units)?

If going with the full size unit, there then seem to be additional choices to consider--high efficiency/power saver options and/or heat strips--either built in (with the Coleman) or add on to the Dometic. What are the pros and cons of the high efficiency and the heat strip options? Does an $80 heat strip in the air conditioner give you something significantly more worthwhile than just putting a portable ceramic heater in the bedroom at night?

Finally, if things are otherwise the same, is there any reason to go with a Coleman model vs. a Dometic model vs. some other model?

Thanks in advance for your help.