I was very impressed with my KG 4s when i got them. However when i added another amp and a set of a kg 2.5 to go all with them as an additional main left and right channle, it really made a night and day improvement. KG 4 are awsome power hungry speakers that lake a certian subelty that the power handely and fullness that the 2.5s bring to the room. the reason i mention this is when choosing a center acually think about complementing the 4s. i am wanting to grave a kv 3 myself but i would recoment a set of 1.5s or 2.5s up front for anyone with a set of KG 4s. My Taste in listening is differnt than many people, But you have the oppertunity to test a pair of 2.5s or 1.5 with your KG 4s you will not be displeased and could help you solve the delema of witch center to buy. I love stl's custom built center and bang for your buck i think would be the way to go but a KV 3 im going to give a shot becuase a friend of mines father ownes one. just dont buy anything polk. any Klipsch speaker would due better.
KG-4, KG2.5 main l/r
two HK avr 520's
Bose 701s Rear Surround Sound
Polk Audio LSi C Center
Two KSW-12 Kilpsch Subs to the inside of each kg 4
polk 8 inch sub to help the bose out in the rear