You're better off not stacking it with anything. It's a killer tune as is. I stacked mine with the Six Gun while towing and it did ok. But for flat out performance I think the Six Gun would hinder it. Besides you run the risk of adding too much timing........
The ATS E-Power is the same as the PPE HOT +2 but half the price. It might be a little more than what you want though. I have also run the predator back in the day. It was OK but I thought it performed better when stacked with the 6 gun.
The stock intake on the D-Max is not bad. With a little mod. you can re use the exitisting housing. You can use that extra $300.00 and buy a predator off of ebay and get much more than 10 HP :D
I had those on my "Yota" back in the day. They held up really well but after a couple of years they started to luster a bit. No matter how long I spent polishing my rims, I couldn't get them back to new. It is true, you do see alot of them around. I've got wagon wheels on my truck and people...