Virginia Gun Owners Forum - VGOF

OK, I'm a pretty experienced with rifles but a true novise when it comes to shotguns.

I've decided to buy a couple of shotguns. Others have advised me to buy something like Beretta. I buy weapons for functionality and reliability. Therefore, I'm not willing to spend a lot on artwork etc.

I'm currently looking to buy one semi automatic and one o/u
1. A400 XPLOR UNICO KO, 12GA, 3.5" or A391 Xtrema 2 KO, 12GA, 3.5"
2. Silver Pigeon or White Onyx.

My problem is that I cannot see the difference between an A400 and an A391 Xtrema except for wooden stock versus synthetic stock. I really like the synthetic but would like to understand what benefits, if any, I would lose if I choose Xtrema over A400. I intend to use this shotgun for turkey, geese, duck and deer.

When it comes to o/u, I'm even more bewildered. I intend to use it for hunting grouse, quail, pheasant (i.e. upland game). As hunting grouse in the mountains does involve quite a bit of hiking, weight comes into the equation. I'm not sure about 12 or 20 ga, 26" or 28" barrels,...
Maybe I should look at the Ultralight model or does the advantages of 3" shots outweigh the slight increase in weight?
Currently, I tend to go for the White Onyx, 20 ga / 28" barrel but I would appreciate advice from experienced upland fowl hunters.