I have one of these available if its of any interest to you ? ( I know its not a whole system but worth a mention)
http://www.ek9.org/forum/sale/42154-spoon-n1-replicas-trackday-friendly.html
I have Fujitsubo Legalis R with custom sport cat for sale soon.
Twin Loop available if track days noise limits are a prob.
Dunx
Not keen on twin loops they are to ristrictive and not much louder than oem thanks any way.
They cant be that restrictive as my old high comp B18C with Skunk 2 cams made nearly 250bhp. I still got called in on track days for second noise check even with twin loop fitted .
IMO RMA01a is the best system you can get!!!
Dunx