The one I said has a 6,000mah battery inside. That can charge an iPhone 5/5s about 3 times. Which Anker astro(122g) are yo talking about? A link would be helpful. The astro mini is only 3,000mah which is great for 1 full charge and possibly a little more. If you carry the Anker astro 2nd gen 6,000mah around in a backpack, you won't notice it that much. Most battery packs, including the ones I said use a micro USB cable to charge. They come with one of those cables. The battery packs can charge at 1-2 amps, depending on which one you get. You can use a PC USB port but that will charge it very slowly and will take 20+ hours to charge about. I recommend getting a wall charger that has a 2 amp output. You can use apples wall charger that came with an iPhone which is 1 amp.
If I were you I would get this package:
Anker® 2nd Gen Astro 6000mAh Portable Charger Backup External Battery Rapid-Recharge (2A Output) Shake-to-Wake Power Pack for iPhone 5S, 5C, 5, 4S, iPad Air, 5, 4, 3, 2, Retina iPad Mini 2, Samsung Galaxy S4, S3, Note 2, 3, Galaxy Tab, PS Vita, Gopro and more (Apple adapters - 30 pin and lightning, Samsung 30-pin adapter, not included)
http://amazon.co.uk/dp/B00F91KMHG
TeckNet Universal 5V 2.1A Dual UK Wall Plug AC Power Adapter USB Charger for Apple iPad, iPad Mini, iPhone, Samsung Galaxy Tab/Mobilbe Phone, TomTom, Garmin, MP3, PDA, Digital Camera and many other devices - White
http://amazon.co.uk/dp/B00GCDLD50