In fact, cottages - by which is meant small, asymmetrical, (usually) rural dwellings of one or two stories and stone, brick, or stucco exteriors, come in a large variety of architectural styles. European-type cottages can incorporate design traits from Tudor, Georgian, French, and Italian architectural styles, with open rooms and high ceilings, fireplaces, and even luxurious elements such as gourmet kitchens, formal dining rooms, private master bedrooms, and French doors. What all cottage styles have in common is their livability - their human scale and design for relaxing, unstressful enjoyment of life.
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.
Ranch style homes are usually long and low with a bare minimum of interior and exterior decoration. The idea is to create a casual and informal lifestyle, usually with access to the outdoors via large plate glass windows, sliding glass doors, and patios or decks. Ranch style home plans normally imply a single story construction with a low and long roof line, with a cross- or side- gabled or hip roof.
Look for reputable designers. There are hundreds of different builders out there and every single one has a different history and reputation within the community. If you take the time to check out all of the available designers, you should have no trouble finding the best in the industry.