One thing I've found to be VERY helpful in advise is: Only take advise from someone with ACTUAL experience with that particular setup or item. You can listen to people all day who have heard this, or heard that, or it's awesome on my 2.5 liter it should work great on your 5.0.
I assure you, once you go turbo, you won't EVER go back or regret it. This is coming from an experienced ex-supercharger owner (twice). I have owned an R-trim and a powerdyne.
That T66 is so ideal for your setup it could't get any better. I only have a 62-1 and I've made almost 550 hp at the crank. One day I will upgrade to a T66. Until then, I could only dream of the "big shaft" (62-1 small shaft, T66 big shaft... you know...lets not go there).
I've got over 40,000 miles on my custom turbo setup. It's completely reliable, and makes gobs of power all over the RPM band. My superchargers were neither reliable, nor as powerful (average, and peak). The current tune I have on my car has been the same for the last 5 months. This only reason I lift the hood is to change the oil, raise or lower boost with the turn of a knob (you can't do that with your supercharger), and to keep things clean. That's it.
If you don't switch to turbo, from this day on you can look back on life and say, "I passed up a great opportunity once when I was young and dumb." Now, I'm not saying you're dumb, I'm just saying you've got a great opportunity to advance in the world of power, and you should take it.
Take it from someone with actual experience. I will never go back.
85 ASC McLaren Capri
79 Pace Car