RadioShack is requiring customers wishing to purchase iPad 2 units to purchase AppleCare as well, and possibly an accessory as well, iLounge has learned. According to multiple reader reports, the stores are very limited on the stock they are receiving, with one sales associate saying that AppleCare was required with an iPad 2 purchase as it was the only way Apple would allow the company to sell the device. It appears some stores are also requiring…