I too suggest that a 30F rated bag sounds light for most people for the areas and time range that you want to cover. No way to know for certain, however; what you might consider is renting a bag and going on a trip in the near future (I think this counts as early season still for three season hiking) to get a sense for what works for you personally.

In terms of manufacturers, I only have experience with Western Mountaineering, but I quite like their products FWIW.