Haven't heard what your barrel length is. As was already said, the size of the blade depends on that. Don't go doing anything like altering the blade depth or width. You may "see" the front sight better, but you'll have ruined the relationship between the front and rear, probably irreparably. If you're going to change blades, the best option is a factory white outline in the same size. Those are usually available somewhere on the internet. Also, if you don't already know, you cannot use the same screw and probably the nut, too. The screw is designed to break when it's removed and the broken piece usually can't be removed from the nut. Replacement kits can also be had, though. And finally, there is a super-tiny pin and spring in the side of the screw that is NOT captive. If you don't want to have to buy one of those, too, please use a baggie or something to contain it when it flies out as the screw is removed. From personal experience, that'll save a LOT of aggravation.
I'm all for making stuff more user friendly, and changing the sight blade to something more visible is probably #1 on the list. Heck, I have a white outline waiting to go on my 4516-2. But do it right the first time or let a pro do it. Have fun!!!