May I ask why a wagon? There is a reason why SUV's are so popular and wagons are a dying breed except for a few remaining examples, which is why there is a limited selection. There are plenty of mid sized SUV's around, possibly better value for money and deliver your needs?
Could you elucidate on the reason? SUVs seem to be worse than wagons on almost any metric and seem to have been foisted on the market rather than competing on equal terms. One pet peeve I have is that boot floor surface area is often minimal and compromised but is hidden by volume measurements reached through increased ceiling height. Saying that, a lot of wagons now are sportsbacks rather than taking advantage of extra space beyond the C pillar.