Are you capable of dating with little emotion? If so go for it. I dated a lot in my early twenties and knew going into that I wasn't looking or marriage or a long term relationship. I was looking to go out and have fun. It was one of the best times of my life. Focus on yourself. If you want to have fun with him go for it.
However if you are the type to become instantly attached I would go very slow. I dated a best friend situation before my crazy dating days, and your story reminded me of it. He would do these huge things to get my attention, when something better came along we'd break up and a few months later he would be back. Even more over the top then the last time. I finally had enough, we broke up and that week he was with someone else( who he married). I was an easy fall back. Don't let yourself be a fall back, don't worry about the best friend thing. From experience I never talked to my "best friend" again after the break up and I am thankful for it.