7 Seater car

[Snowwhite]

I know a similar question was asked recently, but there's a few things i'm needing to know that weren't quite covered. This morning for my school run i used all 7 seats (includes mine) in my Vauxhall Zafria and for the 1st time in about 3 years. Usually walk on my morning school run but drove as it's raining. I have a few new children aswell. I have realised (and forgotten) that my Zafria isn't really ideal anymore. It's a good car but my single buggy only just fitted in the small boot (small due to all seats being up) so i stand no chance if i had to use my double.
All the kids bags were just squashed in wherever and my back is now hurting me from where i had to bend right over to the back to put a heavy 18 month old into the very back seat and a small 4 year old (into the pop up seats.) Kids can't climb into the very back seats through the boot when all seats are up. The car seats that require a seat belt through them had to go in the very back otherwise i couldn't slide the middle seats forward.
It now appears that in 3 years my body has aged and all that bending and lifting in and out of the car has caught up on me! My car is also too long and makes parking difficult and reversing, although my parking sensors that i had fitted 2 years ago are great! It is an estate car.

My questions are: what would be a suitable 7 seater that isn't too long and spacious inside? (Do they come with parking sensors?)

Anyone have a sliding door car? That would be useful and something that i thought about for a while.

My Zafria isn't too bad for petrol ( unleaded) but is high in road tax. I have had it 6 years but it is 8 years old. It is the 1st seven seater i have had and wished i had researched it a bit better before i bought it.
I don't want a massive car and don't want one that guzzles petrol and is heavy to drive, but at the same time i don't want to end up getting one that gives me the same problems as my Zafria. If i change my car i need to get it right this time around! It's not every day that all seats are used, but enough.
I'm after one that is spacious inside and especially the boot for buggies, and easier to put kids into the car seats and not all be crammed in and have trouble doing the seatbelts! I prefer not to have a car where you need to remove the extra seats.
My car also mists up easily and takes a while for the very back to de-mist. (Although that could be the case with every estate car!?)
Thanks in advance