Plan your budget accordingly so that you don't get your hopes too high or settle for less than you deserve. That is, plan your budget based on what you can afford. If a half-million dollar home is in your dreams, make sure you can finance it - visit your accountant and bank manager beforehand so you know what budget you can realistically work with.
Modern home plans come in all shapes, sizes and styles. It will be up to you to find the one that best suits your needs. If that's a contemporary plan that includes an open layout, you can find plenty of great plans available to choose from. Of course, you also have the option of creating your own home plans based on your requirements, be they extra bathrooms for the teens, home office or workout space. Perhaps you want an open kitchen and lounge area, but a private dining room. Maybe you prefer the entire lower level to be open but want the sleeping areas divided accordingly. It really doesn't matter because you can get whatever you want.
Also characteristic of the ranch style are open floor plans which permit rooms to serve multiple purposes. Ranch style houses frequently include separate family, living, and dining areas which can be converted as needed into entertaining or hobby areas, or into extra bedrooms when required. Although a single level ranch house plan with front porch or patio is the norm, there are also split level ranch houses and raised ranch houses which have more than one level of space.
When you are searching for a designer, search for one that is local to the area where you want your home built. Typically, local designers will have a better knowledge of the region, the laws, and the other issues surrounding your new house building project.