I'm in pretty much the exact same situation, it'd be interesting to see what you eventually decide on.
Advice I've got so far has been largely:
- Definitely get an SSD
- Get a 4gb graphics card, 2gb isn't really enough to be happy with DCS (ouch, right in the budget...)
- I've been told to avoid Gigabyte motherboards due to various reliability issues, although that might not apply to all models.
- Avoid AMD cpus, apparently they don't work so well with DCS as it's not optimized for using lots of cores (which, again, means spending lots more money).
http://forums.eagle.ru/showthread.php?t=156203