You can always add a different headpipe for each silencer, the p.b. header from fmf will give you a good boost in the top end and quite down the sound level at the same time. I would recommend their headpipe with a different silencer, worked great for me. The titanium 4 is probably the best silencer from them, that'll give you mids and top end power also.
I was never impressed with fmf pipes, but thats just me, as stated the titanium4 would prolly be there best one. The anodized blue is kickass looking though, id like to have a yoshi pipe anodized like that.