One thing to consider, Laski, is using as much of your old system while upgrading the new motherboard and cpu. Using the slightly slower but workable ram leaves a bit more cash to upgrade to a better CPU motherboard and the performance hit is minimal and an easy upgrade later. The two major components that have to be done at once are motherboard and CPU, buy the best you can afford here, build that into your old system and upgrade as you can afford to from there.
None of the other bits requires a re install of the OS to place into the system as money becomes available for better ram, better graphics card or even better case and power supply. If it was me I would get the 4770K CPU, a quality Asus motherboard (I still feel they give best bang for buck out there and less headaches than most). I would also upgrade to a quality CPU cooler when doing the build initially, easier and no need to remove the motherboard down the road to just replace the cooler.