What I need

Because i am going to live full-time in my motorhome i wanted larger things and more things than the mormal motorhome would need for just a summer holiday.
My wife and i went to France for the summer in 2012 to work and have a holiday.
4 months in total we spent away from home, and living in our motorhome gave me a long time to think and work out what i needed in the 3rd one....and the last one i am ever going to build.

So this is what i need.
Because living full-time in it there are a few different things you need as to if you were just having a 2 week summer holiday.
To consider is you need:-
Large fresh water/grey water and also black water or toilet tanks, because it could be 2-3 weeks before you empty as i will be wild camping also with it.
I want a multi functional and usage motorhome, one that i can do most things in and not be restricted much.
This is being built to what i want and what i need to be relaxed in and very comfortable.
Lot of storage space.
Plenty of room inside, to put all our belongings in.
A large fixed bed.
A garage area to put all the big stuff.
Large bed above cab for people to stay over.
Powerful enough to tow.
A variation of heating options.
Economical as possible.
Reasonable gross weight.
Good grip if i am on grass.
Well insulated.
Large gas tank for LPG.