Good idea, aloha, although when it's down to personal preferences we all come from different places...
We used to have a Toyota Space Cruiser (precursor to the Previa, seats 8) and loved it, even with 4 kids we could split and fold the back-back seat and cram in a HUGE amount of stuff, we went camping in France with 3 kids + 1-yr-old and all our own kit including playpen, buggy etc. apart from huge tent, camp kitchen etc. Unfortunately it was quite old (G reg, can't remember what that is now) and we got rid early last year because it was 100K miles and costing us a fortune - we loved it and miss it unbelievably, we could carry vast numbers of children and/or stuff in the back like bikes...dd1 is moving into a flat for her second year at uni, amongst other things we would like to transport a large Billy bookcase and a Habitat armchair, we can possibly fit the former into DH's Peugeot 406 estate but I have my doubts about the latter and both would have gone easily into our old Space Cruiser...
DH got his new company car last year, I would have loved a Picnic (or Avensis Verso which is all Toyota do now) but his co. wouldn't allow him a "high" "family" car, hence the Peugeot.
Now our eldest is at uni, in theory we hardly ever all go out together, but we do occasionally, and doing it in 2 cars, as SofiaAmes suggests, is OK (in theory!) but when you are driving 100s of miles it seems awfully wasteful - but then NOT doing all the local driving in the empty people carrier is very UNwasteful - are you still with me??? mears, you obviously have this problem too. We kind of thought of hiring a people carrier when necessary but the choice isn't wide and several places only have the Nissan Serena which would not be my choice.
Kathleen, I bet this doesn't help you at all. You don't say how many kids you have. Certainly the Alhambra is meant to be the best of its bunch, cheaper than the others but then harder to find 2nd hand. If you have less than 4, how about the Renault and Citroen vanny things, the Kangoo and Berlingo? They seem to be pretty versatile. Or the Fiat Multipla?