Thanks for sharing your build idea on the forums, and items you mentioned will make a great starting setup but you should also use the GPS/Compass module with the APM2.6 for reasons I will describe below.
The first thing you might want to consider upgrading the radio transmitter. The Devo 10 is great but since a radio is not something that you can exactly crash its always a good idea to get a decent one that will last. I and many others will probably agree that the Taranis X9D is one of the best r/c radios around, and also easy to mod.
The only cables you might need is some deans - XT60 converters, as our 4in1 ESC comes with a deans style connector and the APM power module comes with an XT60 connector, but the other option is to just solder your own.
For those motors and setup I would suggest you use a 3500-4000mah battery pack and as for a charger the Imax BA6C is a great charger for the money. You can find the charger and a selection of batteries off ebay, but its a good idea to check with the seller of the age of the batteries as you dont want to buy some that are over a year old.
Yes this frame should be able to handle a small camera just fine like a gopro, or compact stills camera around 200g or so, what type of camera are you thinking of using?
I would highly suggest you use the GPS/compass module as it unlocks all the cool features of arducopter and also makes it much easier to fly as you can always flick a switch on your TX and your quadcopter can come home back to you. Without the GPS the APM will only be able to keep your aircraft level. But if that is all you want to do with your quad then I suggest you consider a cheaper fight controller like the KK2.1 board.
I hope that answers some of your questions and did not add to the confusion of making a choice , but if you have any other questions please let me know and I will he happy to answer them as best as I can.