We bought our 1st van in April so I know how confused you are.
We didnt know what to buy either, we always liked the baileys and ended up buying a Bailey Senator, the discovery/ranger are the cheaper end of the scale (nice vans though) but you will have to weigh up what you want to fork out and see what you can get for your money.
We bought a very well loved "pre owned" van, we have a luxurious, well made van that will last us several years, we did consider a brand new bailey ranger (which wasnt much more than what we paid for our 2nd hand van)...but we ourselves prefer the top of the range fittings in our senator, as we use our van so much.
But some people prefer a brand new van as they dont like the thought of pets/smoking etc being in it. Take your time and have a good look around all your local dealers, write down all the makes and layouts that you like (even the non-bailey ones) and then have a look at the private sales too and see if you can pick yourselves up a bargain.