You need an architect to draw up your design and then a builder.

Laide - if you want to mind the budget then you ought not to try to do your own house design. The best solution for budget is to start with an existing plan that is about the square footage you want that comes nearest to your layout, then perhaps adjust only a few things to suit you.

If you are ready to invest in this, you need either an architect to lead you through the process or a builder with design services built in.