RE: help needed....
If you are looking for an autoloader, you will have few to pick from that will do 3.5" and are $500.00 - $800.00.
Mossberg 935 is a solid gun, as is the Remington 11-87 Super Mag. They may come in at the above price range.
The most popular 3.5" guns I used to sell were the Benelli SBEII and the Beretta Extrema II, unfortunately, they are expensive.
I feel that you should always buy the gun that fits the best not the brand I like (Beretta). If the Browning or the M2 fit then jump on them. If I needed to pick I would go with the M2. I like the Benelli recoil system and can not afford to feed a 3.5".
Just my $.02
Let us know what you get and post pics.