Sorry for the late reply.
I bought my electric cutout from DMH at www.dmhperformance.com
They are very good quality and sound absolutely awesome.
I personally can't give you dyno results, but have seen posted 12 rwhp after the cats and 20 rwhp before cats from somebody who did.
But the sound as I say, is worth everything especially when opened up on the street. All at the touch of a button.
Typical opening/closing of the cutout is approx 2-3 seconds.
It makes you fall more in love with your truck if that's possible.

 

for a first mod I 2nd the throttlebody. you will see more gains from it than anything else.
later I would add AIRRAM intake, exhaust(cant beat a cutout), and you can do the powerwire but keep in mind it forces you to run premium gas.

 

Look into the Airraid Power Wire also. I'm considering it. Do a search here on it. Someone here bought it for $30.

 

If i remember correctly, you only have to use the highest octane when you combine the PW and SC, if you only have the PW you can still use the 87 (or whatever) octane you normally use...

-David

 

that's only at wot where you get the gains..

for $100 get an electric fan viper or markviii doesn't matter. easy 10rwhp gain cosistant throughout the rpm band.
here's another trick only for track purpose. Power steering and a/c pulley bypass.. ~10rwhp (it was 9.7rwhp or something)