Here's my run. I had it tuned to a set of Yosh RS 3 Race cans and other than that it is bone stock. I found out that the cam chain was off a tooth so that is the low reading and the high reading is after it was fixxed and tuned. Went from 115 Hp at the rear tire to about 158 HP.
I just bought slip ons. I got them from Roswell Fun Machines here in GA. and paid $690 for them. but I had to pay another shop to tune it for me. And that is how I found out the the cam chain was wrong. And all this because I missed a corner and had to have it fixed. You might be able to get them cheaper elsewhere but Insurance bought mine.
As for the HMF Exhaust not sure how good the price is but go here.
P.S. My Busa is a 2000 and the cans are Titanium. If you goto Yoshimura's site they are $725.(75248)
Here you can get them for $632.95
Yoshimura RS3 Race Slip On Titanium Canister #R149SOTI
I've decided to go with the looks. I like the balanced look of the dual pipes. And to be honest the busa already has more power than i got guts --- could be a new family slows you down. 160 is about as fast as i'm willing to push it these days. OR perhaps its the fact that the cager here have a thing about pulling in front of fast moving bikers... not sure but anyway thanks.