Hi Xaeniac,I built it and have a biostar motherboard. Pretty sure it is a Biostar TH67+.
My brother in law had the same CPU and slightly different board. We decided to purchase a 3770k and after market cooler from ebay for about $170usd.We also upgraded his ram from 4gb to 16gb for under $50usd. His 3770k stock runs games just slightly slower than my I5 6600k and when he overclocks to 4.2ghz it's faster. I think this is the best\cheapest option in your situation. If you want to replace the board/ram/cpu then you should look at the AMD Ryzen 1600 as others have suggested or wait to see if Intel's new CPU's on the 19th push the i7 7700k prices lower.