Trago, Midway USA has them in stock,both the 10 and 15 round magazines,as a matter of fact,I ordered 2 yesterday for my 659.
As for the grips,you might also ask your question over at the Smith & Wesson forum. Hope I helped you out.
For the magazines
http://www.midwayusa.com/browse/Brow...1341***8906***
And the Smith & Wesson forum
http://smith-wessonforum.com/forum.php