Both Hobbyking and Gens batteries tend to come with XT60 connectors which are easier to work with than Horizon Hobby style EC3 or EC5. So if you change your ESC connector to XT60 you will be out of the Traxxas ID issue.

I did see that Venom sells their batteries with a universal connector system. This is a nice idea but adds an extra adapter. Each connection point adds a little more resistance.

There are lots of decent chargers out there. Not too many with higher power have built in AC to DC power supplies. When you look at chargers, make sure you look at the max current and max power per channel. Either can limit how fast you can charge. Generally, I think 200W is good for up to 4S batteries and you want 500-1000W for 6S. So as long as you are using 2S batteries, 200W is fine.