Unless intel changes their nomenclature, broadwell is going to be i3/5/7 5xy0(k), where x goes up to 7 and y up to 9, although not in all combinations, obviously. Broadwell-e will be i7 6820k/6930k/6960x. So far there's only been three "extreme" cpu's per architecture.
Anyway, after reading the title again, the i5 4690k is definitely your choice. The extreme cpu's generally feature a horrible price/performance (bang for your buck).