Help ZXR Charging system questions (reg/rec, battery info?)

So in pulling the bike apart to do the EFI conversion, I found that while my R/R works, the plug into it is burned up. So, I am gonna replace it and relegate this one to the spares bin. What's the good brand/hot ticket/not eBay junk to look out for?

Second, the manual doesn't specify the format for the battery, only size and capacity. What MODEL battery do I need? I can't remember what I bought last time I bought one, and when it died I threw it away forever ago. I'm getting close to needing to power up the bike and it needs a battery to do that.

Thanks!