Bootcamp on Late 2012 iMac

I got my new 27in iMac at the very end of Dec 2012. It does not have the 3TB Fusion drive. It also does not have an optical drive. I own a legitimate dvd copy of Windows 7. Microsoft has stopped selling the Windows 7 downloadable ISO. I have been trying for over a week to use boot camp. Every attempt has been stopped at the point where the computer tries to boot from a Windows installer drive. Here's what I've tried:

1) Creating an ISO from my DVD. The Microsoft ISO to DVD or USB utility won't make a bootable flash drive from it. I used the Pendrive Linux utility to make a bootable installer flash drive which works on my PC hardware, but won't boot on my Mac.

2) Downloading several maybe shady Win7 ISOs from Softpedia and Digital River links. The Microsoft utility will accept a couple of these. So does Boot Camp's bootable USB creator. But the Mac refuses to recognize any of these as bootable. They all booted on my PC though.

3) Using an external DVD drive to boot my legitimate Win7 DVD. It will work so long as I haven't partitioned my Mac's HD in Boot Camp. I can get it to boot the Win7 installer if I hold down the option key at boot, then plug in the drive after the boot selector is displayed. However this doesn't work at all after I've run Boot Camp.

Side note: Oh, and when I get the message to hit any key when the mac can't boot, neither my apple wireless keyboard or my USB keyboard has any effect. I have to hard-shutdown the computer holding the power button.

The reason I bought this iMac with updated CPU and GPU was to be able to dual boot it to get okay (but not great) performance playing Windows games, while using OS X, which I love, for everything else. I'm at a loss and have buyer's remorse. Is the only solution to wait for a version of Boot Camp that supports Win8, and for Microsoft to sell the full (non upgrade) version of Win8 as an ISO?

Or do I buy a gaming laptop and connect it to my big TV via HDMI and forget using the Mac with Windows?