Each brand is about the same as far as performance goes. If you're going to be using OPK's they are FAR cheaper to buy from online. Try Fertility Naturopath or Lullaby Conceptions. As far as time wise goes, I think between 10am and 6pm is good. Don't use FMU as it is too concentrated. Just make sure you do it at the same time every day.
Hope that helps! Good luck!

Celsie. xoxox