Before you hire an Architect or Building Designer, it is a great idea to get as specific with what you want to experience with your land, views and living space. Be clear on what you like and don't like as well as your budgetary constraints. Your first description makes me think you are leaning towards something very modern in order to achieve the "openess" you seek. Concrete, glass, steel, not your typical residential project.
Don't be afraid to throw up a lot of visual ideas that your designer can work with, unless you want their vision of what your home should be. Most Architects like that option, as it can be a real ego booster.

It is a great idea to develop a firm design program spelling out what you expect and want from all your home and personal spaces. It always amazes me how little some people will put into that effort, as compared to how much time they will spend shopping for their car. Resale should always be an important piece to your program, especially in light of todays real estate markets.

There are sooo many things to consider in your next step, too many to list here, but start with this guys Blog and it will stear you in the right direction:
http://gloomcupboard.blogspot.com/2012/03/7-steps-to-success-when-building-custom.html
and then this one:
http://www.homeadditionplus.com/home-articles-info/Why-Build-a-Custom-Home.htm

We built our house 3 years ago, and VIEW was our primary focus! Before picking an architect I looked at floor plans online, to get an idea of interior flow/layout; there is a TON online, for all different types of spaces/layout. It also helped get an idea about exterior as well, even though I was much more focused on interior flow/layout, to begin with. Then, I picked 3 architects to "interview" with, which, in the end, helped us clearly narrow down to the one we used, based on the floor plans I had already liked/decided on, and the architects work he showed us for the outside of some of his other work. Then, we interviewed 3 contractors/builders, to settle on a builder. We visited, in person, the builders work, so we could see it first hand. This helped us decide who to contract with - an even more important decision then the architec, in my opinion. While I know this sounds like a lot of work/time, it was well worth the upfront work!! Good luck!!!!

Charmean is correct , search in The Houzz Search .

Thank you everyone for your comments. Sincerely appreciate the inputs. Is it a good idea to hire Architects who do not live in our area? I feel most architects in the area have similar design and model in mind. Ours property is not restricted by HOA and hence it's a clean slate to start with any design. I see some Architects in the midwest/Florida and Texas whose design we like and still debating if it is a good idea to hire any of them.

That is a good option to Explore and how you and the architect go about deciding on the site visits as and when required .

Wonderful property and with your emphasis on enjoying your back gardens, consider landscape illumination to enjoy the nighttime ambiance with the open house plan you wish to create.