Architectural Drawing for Planning, plus Floor Plan Layout Help

I am needing to do some form of single storey extension to my detached property and to re-model my downstairs layout to increase living / entertaining space. I need an architect who can help with space planning to give me 3 potential layout options, 1 as cheap option, 2 as middle of the road and 3 as the more premium but will give us everything we want.

Once confirmed on which option, we will then need drawings to go in for planning permission