Long headers + X + hi-flow cats?

Hello stangers,
I have a question. I was checking the long tube headers and found a combo of LT´s + catted X. Right now I´m only able to find MAC´s LT´s and prochambers without cats or the JBA´s with an "H" catted combo.

I´m confused, I can swear I found a combo of an LT header (1.3/8") to an "X" with cats. I´ve looked at BBK, MAC, JBA, Hookers, Bassani again and I´m not able to find it for around us$800.00

Am I just having some bad alcoholic nightmares?
Does anybody with a similar setup has achieved the +20whp (average) advertised by the manufacturers?
With stock mufflers, the tone must go deeper, but how much? (compared to any exhaust system by itself? LM´s? Borlas? etc.)
They are obviously not for vehicles that must go to emission testings, but how will they affect me if I have the cats? (I must pass inspection and it consists of CO + CO2, NOx and HC´s (hydrocarbons?? not sure of the exact translation) BTW, CO2 + CO = A/F ratio and I passed it with an excellent 14.6 at idle and 14.5 with load -SCTII by brenspeed, 87 oct and C&L-.)

Thanks in advance!

Thanks for the input. SLP´s are very well recommended by a friend with an LS1 engine.

you forgot the link, but I can look at dealers of SLP. Anyway I´ll be paying a lot for shipping since I must import them to Mexico...
Again, very appreciated!