I am in the market for an external battery pack for my iDevices. I have both an iPhone 4S and an iPad (first-gen). In a perfect world, I would like a battery pack with the following qualities:

• Enough juice to charge the iPad fully plus enough juice to charge the iPhone a couple of times as well.
• At least two USB ports, so that I could charge both the iPhone and the iPad at the same time.
• 2.1 Kilovolt/10 Amp output, on at least one of its USB ports, so that it can actually charge the iPad.

As long as it's not larger than the iPad, size won't be much of an issue.

1. How many mAh do I need?
2. Does anyone have any suggestions as to specific products?
3. Does anyone have any information on products to avoid?

I think that's about all I can think of. Please help me out. Thanks in advance for any and all assistance.

I've used this one :New Trent Dual-port Pack IMP50D 5000mAh with 1Amp: Amazon.co.uk: Electronics (sorry for UK link, but I'm sure you could find it on amazon US), the only thing it doesn't satisfy on your list is it only charges the ipad about 50% from a full charge, so you may want to look for one with 10000+ mAh.

I have the isound 16000 mah power pack 5 USB model cgi ad-4544 from amaZon it can charge the iPad twice and still have power to charge my iPhone twice I can recharge it using my solar panel or wall plug
This item is the best on the market and cheap