quick performance

So I’m to the point I need to order my rear end for my build. Quite honestly I don’t know much about what differential would be best for a street application. I want posi for sure but can someone help out with the pros and cons of these options? Sorry in advanced.

Looking into buying a 9 inch from Quick Performance and also want to sort my rear brakes out at the same time. I have done a bunch of reading on the 98+ Blazer rear disc swap and it would be nice to do that and the Blazer front spindle swap, keeps all the brake components similar. My...