Hey Bob! 

Depending on the type of music I'm playing, I'll swap picks. For my Electric Guitar, I have been playing with a 1.5mm Ernie Ball Shield pick. On my acoustic, I like thinner picks, anywhere from 0.6 to 0.88 mm, depending on whether I am strumming or picking a bit and strumming. Heavy strumming, I really like the thinnest pick I can find. This Amazon.com: Jim Dunlop Acoustic Pick Variety Pack - 12 Pack : Musical Instruments has a different assortment with different types of grips. I recommend finding the size of pick you like and then finding the grip type you love, man. This variety pack has a decent mix of both. I found I don't like picks with too much grip because I'll pinch them so hard that it makes my hand tired after about 30 minutes of playing. There's also Snarling Dog Picks; they have a smooth balance of grip for fast strumming, and they are really light. 

Picks 100% effect your tone. Find the pick that makes your guitar sound how you love. 

Be Safe!!!