I'm biased to the saiga (own a 12, and two 762x39s). they are extremely reliable, can be highly customized, and relatively cheap.
Right now your problem getting a saiga is supply and demand. Last year they were selling NIB for $439, but because the russians are 6 months behind on shipping, prices have skyrocketed. I got a used one last month for $500, which was a steal. Gunbroker has them for $700, which is a rip. If you are really interested in buying a saiga, I suggest you post a WTB ad here as well as the saiga forums (forum.saiga-12.com). That's the only way you're going to get one for a reasonable price.
If you do go the saiga route, you will be happy. They have 10 round mags available as well as a 20 round drum. You can convert it anyway you choose or pay to have someone else turn it into a beast. there's a plethora of stock options, as well as hand guard and general configurations (everything from ak-74 to sbs to MP5 to you name it). I'm converting mine as soon as the parts arrive and if this thread's still going i'll post pictures.
As for the antis, if there ever is a ban you can be sure the saiga will be listed (already is in some states (CA)).
Sorry I can't help with the mossy, never owned one.