Regarding planting kinda close to the pond edge, I cannot see a logistical mistake in the making. The other forum members can correct me on that point. Consider, tho, how the view will change when they grow up to be big boys. How will the sun play off of them? Will they be in an area to provide a nice reflection off of the surface? Also, a random planting pattern should be practiced. The distance from the shoreline should vary to create an appealing and natural design. Go on-line to your official state website and work your way to the USDA and/or soil and water division to find a listing of the types of conifers and how they respond/grow under differing conditions. If this info is not available there, reach out to your county NRCS office. Along with this research, practical input about the difficulty of rearing conifers relative to the surrounding evironment and wildlife should be available and considered. ie; deer eat some conifers and stay away from others...some conifers cannot survive under the filtered sunlight of a surrounding forest canopy...etc. Finally, consider the mail order houses if you have the time to wait for smaller stock to grow. Call one or two and consult their people for fast growers, limitations, etc.