Ameriglo and Warren Tactical are also great choices for fiber optic sights. My eyes prefer blacked out rears.
I also prefer a blacked out rear and a Dawson front sight, but trying to find an adjustable rear sight for my SIG P226 was almost impossible until I found some LPA sight (Italian) that had both FO front and rear. I bought them, removed the rear FO's and blacked out the holes. Love them, and have decided that any time I replace factory sights, I am going with an adjustable rear.
If you don’t mind me asking, do you shoot a specific division? I debated looking for an adjustable rear but figured for what I do (USPSA Production, use factory ammo) fixed would fine. In my experience, which I admit is quite limited, there’s not time for a perfect sight picture so fine tuning sights wouldn’t really be worth it.
Appreciate all the replies so far.
It is still important to get your sights dialed in. You will still have to shoot the same 25-yard mini-poppers whether you are shooting Production, Limited or Open.
Most times, you can adjust windage (left <-> right) just by moving the rear sight slightly in its groove, but to adjust for elevation, that is not possible unless your rear sight has the ability to adjust built in.
I ordered a set of Tru-Glo sights, and could never get them adjusted properly for elevation no matter what I tried. My gun had 8R/8F sights, and tried the Tru-Glo 8/8 sights, no good, so I returned the 8F and ordered a 6F, still no go. Most of my other guns have adjustable rear sights, which make it so much easier, so I went out in search of something that would work with that gun, and the LPA sights were the only ones I could find. It might be different with your 320, I am not sure. In your case, you might be fine with standard sights, but after my fiasco with the Tru-Glo sights, I swore I would never install after-market sights without the ability to adjust them. YMMV.
Good luck!