Consider getting a turbo nozzle for your current pressure washer before spending the money to rent. It should work much better than the current nozzles you have.
If that doesn't work, both 2700 and 3500 psi will absolutely strip paint if you're not careful. Either will get the job done, you'll probably want to use a 45 degree on the 3500 or a 35 on the 2700 to avoid gouging or stripping.
Now get a rotating nozzle. You'll thank me later.
Get a rotating nozzel if you can, they work like a charm. Many times I have had a normal 20 deg nozzel fail and the rotating make short work of it.
Something like this https://www.amazon.com/Pressure-Washer-Rotating-Orifice-Connect/dp/B00IDAC21Y
turbo nozzle - buy one now, thank me later
its a pressure washer special tip.
its a pressure washer special tip.