My HD tool is an 8 shot Mossberg 500 w/ 20" barrel (one that they sell at Big-5 for $300, you know the one).  My setup is an added rail red dot on top.  The rail has a slit down the center so if there is nothing mounted you can still use the bead sight properly.  I also have a snap on fiber optic front sight.  I plan to customize the red dot to a quick release so if it fails I can remove it and use the fiber optic sight.  The issue I have is the cheek weld height.  With the stock cheek weld my line of sight is to low for the red dot so I got a Voodoo Tactical Buttstock Cheek Rest, but using this, when the red dot comes off the cheek weld is to high.  What I am looking for is a rifle.shotgun style stock that either has an adjustable comb or a stock that you can add an attachment to raise the cheek weld and remove it rapidly. There is something for the Flex models but I do not want to spend the money to upgrade.  I also am not interested in a pistol grip so that rules out a lot of options. So far I have not seen anything on the market that suits my needs.  I find it a bit odd as I would think this would be a typical thing that people would want, but then again, I guess most people who add optics to their HD shotguns probably go with a pistol grip and M4 stock adapters.

Any help would be much appreciated.  Thanks.

You can always try the Magpul SGA

They have an add on cheek riser that snaps in place securely and I believe they have different heights too.

On a side note... They kinda look cool too... especially if you pair it with their forend.