Don't rule out an Ithical 37; they are a very good "Browning BPS" for less money, but they too are starting to go up in price.
For one that takes choke tubes, you will have a hard time finding one and if you do, much more than a BPS. The very best pump gun you can buy however. BPS is a great gun too, but starting out I would get a Mossberg 500, birds won't know the difference and it is available everywhere for a decent price.