Pitching rate

I brewed a beer 15 days ago with WLP001. I pulled some yeast from the bottom of the conical 6 days ago and put it in the refrigerator. I took a the good yeast, not the bottom and not the top. I am brewing 12 gallons of 1.048 beer tomorrow and am wondering how much yeast would be ideal. I checked a couple sources and one tells me one 8oz cup and the other tells me 2 8oz cups. Is this because one is expecting the thick slurry and one is thinking it will be a thin slurry?

It's pretty much impossible to gauge yeast that way. With 01, I'd error on the high side. You want it to be a clean fermentation anyway, so the risk of underpitching is worse than the risk of overpitching.