This is how I interpret your situation. Pumped transfer from a collection point to a discharge point over about 150' of pipe with a slight high point in the discharge piping run. First off, there isn't any reason to go to 3", the head loss for 43 gpm with 150' of 2" PVC is about 6'. If you have your pump curve I would assume it's perfectly capable of handling this. Go to all 2", trench the line in where it is in the yard, go under the sidewalk and penetrate the curb. Use a stainless mesh to cover the end of the pipe and you are done.