I recommend tunnel time. I am in a similar situation. I'm still working on my belly skills and am by no means am I very good at 4-way dives yet. I did some tunnel time and the confines of the tunnel as well as the coach you have in there helped me realize how I was reacting in the sky. Tunnel time helped me learn to be more stable, react to level control better, and have a reference for what I was doing in the sky (not that I was completely lost, but the tunnel showed just how much I move around without thinking about it). Try to save $100-$300 for it, get it taped and review it. Also, you and your friend sound a lot like my friend and me. Work on your exits together, that is where so many jumps for me have gone wrong. If you start messed up, its hard to get back to a good skydive.