My suggestion would be to;
BUY NOTHING !
Sure, go out and check out whatever you can, make sure you have a good idea of what your looking for and to what pupose you intend to use it.
For example OFF ROAD going bush occasionly, river crossing, rough dirt roads, or staying on bitument and away from dirt and gravel roads.
I must point out here, that the BEST places to camp out, are usually always off dirt and gravel roads, so keep this in mind.
Also, if you haven't a 4WD at this point, in future you may wish to upgrade to one, so make sure your camper will be of build to cater.
Now, the reason I've suggested you NOT BUY at this point in time, is because I STRONGLY suggest you HIRE a camper trailer of your choice for a weekend or longer, to see if it fulfills your needs.
In many cases, manufacturers will even count the hire fee and deduct it from your new purchase should you decide to buy one.
Now another BIG decision, do you choose a SOFT FLOOR or HARD FLOOR ?
The difference being cost and ease of erection. A HARD floor is generaly easier and quicker to erect and stays OFF the ground, very useful in inciment weather and for littlies keeps dirt out.
Soft floors on the otherhand are a little more complex to erect, can be punctureed by sharp objects and are colder directly on the ground, plus in incliment weather, water can and does run straight underneath the floor often draining warmth away with it.
For what it's worth, my suggestions.