Walk around the pond, vary your distances, see what looks right, measure the distance. Pond size matters, too. A 1 acre pond can be completely viewed even close up on the pond, while a 4 acre pond you'd need to sit back a ways. This is all personal preference...maybe I'm missing the thrust of your question?
On another topic, apparently congratulations are in order - you ended up buying that parcel evidentally? Good job! Any luck on finding a contractor? Check all local pond owners and ask them who worked on theirs, NRCS, etc.