Hi Kallen,
A few thoughts.
Firstly the link to your choice of van doesn't work.
Regarding a full size annexe. Not trying to tell you what you need, but I would advise you that many many folk think they will need a full enclosed annexe & once on the road find that rarely or never use it. If you have room to sit inside when the weather is bad, or the mossies are biting you probably don't need one either. An awning is essential for shade & shelter though. Annexe walls are mainly only used by folk who stay put in one location for long periods (which may be your plan), but are a considerable weight & a PIA to put up. If you decide that a full annexe IS a necessity you should be able to pick one up that has had no, or little use for way less than new cost. A length of shade cloth across the front of the awning is a compromise that many use if extra privacy is needed, is much lighter, & cheaper & quicker & easier to put up.
Regarding whether to get the van first, or clear the debts first. Always good to get rid of debt....BUT ...... IF you are certain about what you are planning, getting the van first helps to cement things in place & gives you a sense of progression & commitment. IMHO it makes the dreams coming true seem a bit closer. It also gives you the opportunity to get the van how you want it based on a few 'shakedown' weekends etc away, as I can guarantee what you will think is important in the van will change once you have used it.
I would also advise that you take your time choosing a particular van. Join
this forum & ask heaps of questions. You will be better informed, plus will probably save yourself some money - it's a buyers market.
The smaller the van, the less it will restrict where you can go. Many national parks don't have drive through sites, making bigger vans a pain. There are also very few genuinely off road vans. Plenty say they are, but are really only suitable for reasonable gravel roads. Ground clearance, departure angles as well as general sturdiness conspire to make many so called 'off road' vans unsuitable for off road. IMHO the two choices are to either spend big bikkies on a genuine off road van, or to buy an older van whose owner has modified it over the years to survive the thousands of corrugated kilometres. The latter may not always be pretty, but will likely be dust proof & sturdy.
Good to hear that things are progressing. :)
Cuppa