Re: acrylic vs latex?
Kilz is a stain blocking primer and will accept any type of top coat you choose.
Sherwin vs Valspar. They are both good paint, the Sherwin is probably just a tad bit better about thickness and anti-spatter qualities. I've used a lot of both brands and typically used Valspar more because it was more convenient to purchase than Sherwin, which was located in an area of town I rarely traveled. Valspar was also cheaper though that may not be the case for you with your Sherwin discount.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!