Oh, boy!
Do it, do it, do it!!!
My son-in-law and I took the two-day defensive handgun course, last October. Originally, we were going to do the four-dayer, but real life got in the way.
I'll compose a PM with details and recommendations. Give me a day or two, there's lots of stuff to tell.
In the meantime, make up a list of questions and send me a PM.