FMF's have decent power down low but completely fall on their faces on the top end.  Seems like i remember them coming off the pipe about 5500 RPM.

Typically, the "Big Boy" pipes will come on the pipe about 4000-5000 RPM and not fall off until about 7500-8k.

They will cost you a good bit though but they're well worth the money with the HP and RPM gains.

A great budget pipe is the AAEN and it performs similar to the Hall and Q pipe.  Last i heard they were about $380 raw.  Be sure to ask for the new design.  If you go with a Hall or Q pipe you're gonna spend about $1000.

As far the carb goes, i prefer the bored 88'+ stock zilla carb over a keihin carb.  They are just hard to fine tune compared to the mikuni.

a 185 does sound pretty rich for an FMF at 2000ft.  I wouldnt imagine the FMF pipe would require much of a main jet change over the stock pipe and I dont really know what the stages mean in terms of porting from Trinity.  I had a Trinity motor about 12 years ago and hated it.

Mr. Hall is absolutely right about the intake tube.  Don't run the filter clamped on the carb, they are just hard to tune.  You need at least a 3" tube coming off the carb.

My advice, since you just got the bike, is to have the head sent off to get reshaped and to set your squish clearance correctly.  Need to eliminate the detonation issues first.

 The joys of owning a zilla!   

Also, welcome to the forums!