Very large planting scheme

I have a very large lawned area of circa 2.5 acreas. Our house is a two story house set back 120 meters from an very quiet road. As you look at the house from the road I have post and rail fence on the from circa 70m accross. On the left boudry ditch I am fortunate to have a line of old oaks. On the righ I have post and rail fence. The length of the site is circa 300 meters and i have a hedge growing at the back of our house so that I dont have to mow the whole site. Thanks We have an ‘S’ shaped drive way from the road to our house.All of the drive way on left and right is in a lawn.Because of the substantive space I am looking to create an old feel to the driveway incorporating perhaps laurels, Rhods’ and a mix of suitable larger srubs. The lower the maintenance the better.Our soil is clay soil so presently because of the good weather it gets extremely dry and hard. In wet wetter it gets water logged and ver very heavy.Can you suggest a range of suitable srubs/trees suitable for this site? Also is there any ‘heritage’ type designer I could approach to discuss this in more detail? Many Thanks and best Regards Richard Riordan