I don't blame ya, buying and installing crap, will leave you buying a good one when it busts.. I don't have any experience with Sand Craft diff's, but their RS1 propshaft is incredibly well engineered, so well, I had to contact my vendor, and he his rep, to figure out how to install it, and now that I know, it's genius compared to stock.. And you can lubricate the bearing too..
My RS1 front diff took a pounding in UT, and nary a complaint. I was concerned, and I'm pretty sure my 900's front diff wouldn't take the abuse I put on the RS1.. IF I were ever to replace it, I'd consider the SCR one equally.