In general, when choosing between a TURP or open prostatectomy most physicians recommend TURP.
However, with stones that need to be removed the situation is a little different. I am not able to recommend to you which of the two options would be better because there are many factors involved. 2 surgeries means also 2 anesthesia exposures and 2 post operative recovery times. However, having 2 surgeries at one time generally is a more complicated procedure.
I would recommend you talk with your surgeon to go over both options in detail. This way you will have all the facts and can make an informed decision.
Advice and opinions given are based on the information provided and must not be considered an official medical recommendation. The limitations of the internet prevent an appropriate evaluation. Always consult your doctor if there is concern.