Gerber and some questions

Just found this site. I love it!

1) I need to replace an old Kohler toilet, and have pretty much settled on a Gerber 21-302. Do I need to worry much about the Gerber matching up with the drain line dimensions and stuff in there now? (Drain line height, distance from the wall.) Or is all this pretty much standard?

2) What does a 12" rough vs a 10" rough mean?

3) I'm finding that it's not that easy to get this toilet myself, I'm just a normal guy, not a contractor. I need to find a contractor in my area? (San Jose, CA) Or maybe if I hit a professional plumbing store here, they could order it for me?

10" and 12" rough-in are the dimensions from the finished wall to the center of the closet flange (where the bolts that hold the toilet down are). There shouldn't be a problem as far as everything matching up to your old set up. Purchasing the item is probally the toughest part about the whole thing since Gerber doesn't sell to DIY stores. Not just any professional plumbing supply house will be able to get it for you. They will have to be set up with Gerber as a vendor. You may want to call Gerber and find out if anyone in your area carries them.

safest thing, don't make assumptions. While the standard may exist, there are implementations which vary from toilet to toilet. If it is designed for a 12" rough-in, AND the dimension is 12" for the flange placement, any toilet with that dimension should fit, if it doesn't it should be considered defective. But, many times the flange is a little further away (not a problem, just a bigger gap behind), or a little closer. Not every toilet has the same leeway in that dimension - it MIGHT not fit. Safe thing...measure first, then decide.