You could try this, too.
DO NOTHING. Shoot some 2 1/2 ammunition in it. Decide, after a box or three, if you like the gun. THEN make the modifications. You should be about $140 dollars ahead of the game if you decide to sell it. Plus, the next guy doesn't have to live through/with your modifications, and won't be able to use your modifications as a tool to negotiate with you-"I would have liked it more if it still had the full choke, will you take $400?"
Best,
Ted