I owned KLF 20s and now own Fortes and the Fortes and C7 should work great! The KLF 10s and 20s are very good speakers but it is not a upgrade sound wise over the Forte IIs.
If black speakers are a must do to WAF then post on the upgrade section of the forum about how to paint your Forte II in black or even cherry veneer. There are a lot of great people that can help.
If you don't want to paint them then check Craigslist, Audiogon, and the Garage sale section on this forum and a pair of Black Forte IIs will show up eventually.