I don't have the magic answer for you, but for as accurate as possible (at home) for measuring the body fat is the tanita BC-535.

This is as close as you can get and more important as accurate as you can get.

It give very good indications on
- body weight
- fat %
- bone weight
- muscle %
- water %

This is all you need.

Further in the attempt to do something about the roll's is the waterrower (waterrower.com) this is 86 % of all muscles a person has.
It's very effective, but is not the miracle for everybody.

I hope this is some usefull information for you and others.