To charge multiple batteries you will need a Parallel Charge board, and don't cheap out, get one that is a "safer" charge board with fuses or Poli-fuses (they are like a circuit breaker that pops on heat and resets once cooled. It is hard to beat the JB charge boards for price and quality (cost more because they have Poli-fuses) but are limited to one cell count so you would need a few of them. There is no board that has all the connectors and cell counts you will ever need, so you won't be able to get 1 board that fits all the bills.
I would suggest weighing these as they are the best/best bang for the buck.
XT60
Easily and safely charge and balance up to four batteries in parallel
www.progressiverc.com
XT30
The perfect marriage of safety and convenience, our new safe parallel boards are ready to make charging hassles a thing of the past. The board comes fully fuse protected, with 15A blade fuses on the main circuit and self-resetting polyf
www.progressiverc.com
You may need to shop for another board later if you get into newer/rarer options in the future like XT30 and 6s
For chargers it is hard to beat the iSDT line, look them up and compare the capability to others for the cost and let us know if you have questions.
Keep in mind, none of this stuff is cheap, you can always get an IMAX B6, but it will hit its limits early for you and you will need to buy another one anyway. You can plan on spending about $50-$60 for each charging port the charger has, and here is a good one in the ~$120 range.
The X2 AC Plus Black Edition Multi-Function Charger by Hitec is a quality built remote controlled airplane accessory. See all our RC product options online at Horizon Hobby!
www.horizonhobby.com
I have multiple chargers and multiple parallel charge boards, because I have every connector type and cell count out there almost. Batteries are a big expense, and so is a decent charger that can handle the needs for parallel charging (lots of amps) and charging a few different types at once (multiple ports)
Try not to be shocked that these things aren't cheap, but look for sales and reviews, and then build over time what you need.