I will be receiving a nice M451 very soon from another AC member. I have always wanted to try one and have been intrigued about the batteries. I have read from most that they are a good investment and improve sound quality. There seems to be a few options from Virtue in kit form, but I really don't know what I need. Is there a thread that covers all the various options, pros and cons? I would be interested in the kit, DIY, used or other brands. I am confident you guys can guide me to lots of resources for this project.