When considering length and weight, make sure you stay close to your payload rating, which (as mentioned) is on the yellow sticker on the driver side door. Based on what I have seen, I have similar capacities with my Tundra.
We have a Surveyor Cadet 29SQBLE. I tow it without much issue unless it is really windy. I do wish I would have been able to find something a little shorter, but the weights are well within my limits (5615 dry, probably about 6500 loaded), except the payload might be a tad over (I'm okay with that).
As far as the other stuff, I haven't seen anything that's wrong. Your #1 priority should be what you can safely tow. You need to be happy with the layout. You need to be happy with how the camper is built and what it is built with.
My only unique advice is to try to buy your second camper first. We were told by many that most people upgrade after two years, usually because of space. We had initially picked a pretty small (though still large enough) and inexpensive trailer. After talking to several of our camping friends, we realized we needed something with a slide (the one we picked did not have one). With that in mind, I believe we successfully purchased our second camper first, and I am already shopping for our third :)