Why should you care what I or anyone else prefers when you are spending YOUR money? I have shot double and single triggers and straight and pistol gripped guns and have not found it made any difference, other than what I liked to look at. I do like a straight grip for a lot of things but on a heavy waterfowl gun I did find a pistol grip did add some control in awkward shooting positions.
I don't see you finding what you are looking for in a new gun anywhere close to your budget. I would suggest you look for a good Browning BSS or Winchester 23 and then look at having a REPUTABLE gunsmith such as Brileys install the tubes. Can't stress that enough, as a bad tube job is really bad news, and if you plan to shoot steel a set of tubes with most of the constriction beyond the original barrel will likely be the best way to go. I have had both models, in fact of all the SxSs I have owned I have only kept the BSS Sporter with the straight grip and single trigger, and they are well built and reliable, although of the American style rather than that of the British game guns. If you found a Beretta you liked - long odds - in your budget that would be another contender. I tend to heavier loads so that was what I always preferred. Good luck.