I have never used straw for snakes, I have used it for horses!
I personally like aspen and I use paper towels as well as news paper on occasion. you will however get a bunch of opinions on the subject
As far as temps are concerned there are a few opinions on that too! Here is mine... first I like to have a gradient so that the snake can regulate his temp, having said this I try to maintain a range of about 78 degrees to about 87 degrees.
I hope this helps!