Whats wrong with google? Loads on PID. You will likely need to read up a bit on it first, PID needs tuning. So without ant information other than water bath, it would be difficult to suggest much. Take a look at Google (it wont bite), see what looks most suitable for application, any problems with the implementation then come back with specific questions.
If you just want something designed for you, then maybe one of the freelance sites might be a better place. Although you normally got to pay them for working for you.
One other pointer, giving people a negative rating because they dont just do your work for you, is pretty bad form for a new member to do. Try the same on another forum, I bet you get the same result.