I'm thinking of building one, and coming up with a list of what I would need

thanks

Good question, I have been wondering the same since I have been thinking of an overpriced 410 toy for my nephew (and of course myself)

I finally got a Saiga 12 a couple weeks ago and have gotten it setup in the stock now.  I'm almost ashamed I had the stock for 6 months but no gun after waiting so long on the stock I forgot all about it.
I got the short Carolina Shooting Supply rail and had to cut about a 1/2" square of the plastic off the top of the Kushnapup to make it fit, but with a PA Micro I like the setup so far.  Haven't gotten to shoot it yet though.  Here is the link to what I did, and also I recommend buying the Tapco buttpad to modify so you don't have to cut off the tangs.

Short Rail
Pad

James

Using the short rail on mine. Height seems to be perfect for this type of reflex sight despite it perhaps looking awkward in photos.

http://i1179.photobucket.com/albums/x383/WLJohnson1/Kushnapup/IMGP7199-rs-1.jpg?t=1347294500

Not sure why you had you cut anything as mine cleared the stock just fine. Unless you got the non-Kushnapup one, the Kushnapup version is a little higher to clear the stock.  They were selling at the time I got mine the regular rail and the k-pup version separate but checking just now it's seems they have merged the two into one product.   Plus at the time they didn't have the longer version.

get an ultimak gas tube rail for the Saiga 12.. Will require a bit of smithing to attach it in the front, but it's worth it.

I saw some talk on an old Saiga forum thread about a taller dovetail, but didn't see an option to order one.  Cutting the stock didn't bother me at all, it is an unimportant edge and is completely covered by the rail and sight.  The longer Ultimak does seem nice, but overkill for what I wanted to do for now.

James

Thanks James,

the short rail installs without any permanent mods to the saiga itself, right?

Just tap out the rear sight
Insert the new dovetail piece
Tighten the lock screws
Install rail on dovetail piece