We’ve fitted plenty of B14’s that sort this issue, and level the ride nicely whilst all giving a very comfortable and compliant ride. They also sort vehicle handling positively and making it more car like and less van like in the process. Roll bars are a great upgrade for campers, as has been proved many times, and are worth looking at.
We run demo vehicles running lots of different set ups so please come and try for yourself.
Unfortunately this is all more than your budget, but it worth spending to get the right result that suits you.
Our advise is to try a few setups before deciding as there are lots of options out there from springs, to shock and springs all the way up to full suspension kits with adjustment.
HTH