Need advice on Mac+Gaming PC purchase


The Backstory:

I am a Mac user, but also a console and PC gamer. For the past 4 and a half years I have used my 24" iMac with 512MB video card with Boot Camp for all my PC gaming needs. And it has been pretty good, until recently. My iMac needs an upgrade.

The Question:

What I need advice for is this; Should I buy a top of the line iMac again and use it for Boot Camp again, or should I buy a lower end iMac and a gaming PC as well?

The Breakdown:

Possible high end iMac purchase: top of the line iMac with better video card (4GB) and all the extras - ~$2500

Possible low end iMac purchase - base model iMac with 16GB RAM and a maybe fusion drive - ~$1700 (pretty sure this model has integrated graphics, which kind of sucks.

Possible PC purchase: I am using Chris Grant's PC build as a template, since I want a smallish form factor gaming PC that will be hooked up to my TV. Here is his part list.

The Final Word:

If I buy the low end iMac and the gaming PC, is it too much overlap? 1 machine vs 2? Should I just go with the top end? All opinions are welcome, but please don't to talk me out of the Mac purchase. Let me know if you need any more info.