The i5 4690K is the best when it comes to gaming CPUs.There practically nothing that can beat it,except maybe the i7 Haswell-E's or something,but the 4690K is a great choice nontheless.
If you already have the 4690K,I would suggest getting an R9 280. Good performance for the price. Go with a Sapphire,Gigabyte,ASUS or HIS R9 280,all are great GPUs and have great coolers.Also,you may need a BIOS update on that H87M-PLUS before using the 4690K.Also,you won't be able to OC the 4690K on the H87M.
However,if you do not have the 4690K,I would suggest getting an i5 4440.Similar performance like the 4690K,but cheaper.This will allow for a stronger card,such as the GTX 770/R9 280X.