Don't know where you are located but here's what I would do.
I'd go to the biggest/best local trap club and ask if there's anyone there who would help you pick a gun. This person will likely be a competition shooter and will have a whole lot of knowledge about GUN FIT.
Your primary concern here should be getting a gun that "looks where you look", in other words, that FITS YOU.
Even in the less expensive models, there are variations in the three key measurements: drop at comb, drop at heel and pull length. Find out which one fits you best and buy that one. There isn't going to be that much variation in cost on a decent semiauto. So, do yourself a favor; buy the one that fits you best.
Shotgun fit breaks down into five basic categories:
1) length of pull-the distance from the trigger to the rear of the stock;
2) drop at comb-the distance from an imaginary line extending straight back from the rib and over the comb down to the top of the comb;
3) drop at heel-the measurement of this same imaginary line extended even farther down to the heel of the stock;
4) pitch-which is the way the stock "twists" in relationship to the receiver and affects how securely it will fit into your shoulder; and
5) cast-which is the slight bend of the buttstock as it angles either to the left or the right of an imaginary line running down the length of the rib.
Does your shotgun fit?