I have a 2-horse straight load featherlite. It’s an older trailer, so not quite as large as your specifications, but it has been a great way to go camping. Seems to have good ventilation, sturdy, hauls nicely, lots of space. A lot of course depends on your budget. (My trailer was $5000, and after about $600 of high-ties, shelving, hooks etc, is set up just the way I like it.)
A friend has a newer trailer (I cannot remember the brand) which is a wide straightload, with a walkthrough, and 2 exterior doors in the dressing room (one on either side of the trailer). This has been very handy when she trailers us somewhere, much easier access to the trailer. And while you lose some wall space it is nice to access from both sides, especially (at least where we go) when sometimes finding an easily accessible camping spot can be difficult.