Thanks for the replies. I should have specified the range of the 2d map is relativly small when compaired to the surface of the earth. The area that i will be working within is about 649,947 km^2. From the 49th parallel to the 60th parallel (all of the gps coordinates that i have worked with so far haven't been above the 54th parallel). The actual working area will likly be smaller (more like half or less) than those numbers, but the numbers above are for sure the max area that i will be working with.
In reality a 0.3% error tolerance for my purposes will likely be fine...and from what i've read/understand, the smaller the area the lower the errors will be. Thanks so far for the help!