If you're looking for an 8.8 with t-lok and gears, Paulboy over at mustang collective has a sale right now. $700 plus shipping for 3.73's.
I got mine from him earlier this year.
And yah, the Powerhouse turbo setup kicks butt.
I went with the X-Charger though. A little cheaper, and easy DIY install. But a little less hp too.
Also, you can get an aluminum driveshaft from Shaftmasters for less than $500 still, I believe.
2007 Satin Silver V6 / Explorer Express X-Charger #67 - Xtreme 2.6 - INTERCOOLED!
AEM, MSD, JBA, Zabteck, FRPP X, Dynomax bullets, Pype Bombs, J&M, Steeda, Tokico d-spec, H&R Race, Eibach, Shelby Fays2, Shaftmasters, 8.8, t-lok, 3.73, OE Wheels Cobra R 18x9/10, Nitto 555 255/285, Hawk HPS, GT/CS F/R fascia