Imac a1311 Boots to Disk Utility - Reinstall OS X

I recently purchased an Imac (a1311 - EMC2308) from an auction. Now I'm to trying to restore it. I thought I somewhat knew what to do, however I believe I've messed it up further. So here's the current situation. The imac boots up to disk utility as I erased the drive. However, it appears it had OS X Maverick on it. and I've tried to reinstall, however it make me a log into my apple account, and I don't have maverick associate with it. It doesn't give me an option to download Yosemite. If I log into my account, it just tells me it's temporarily unavailable. I've got a downloaded bootable OS X :Lion, however it does not see the USB drive with this on it (formatted to Apple standards). I tried to utilize the pressing "option", but it just shows recovery HD (however there is nothing in this folder) and it does not see the USB. I tried to the option R, and it goes to the recovery HD, but as I said earlier - nothing in that folder. Help.