i wouldnt expect that thing to be out any time soon...the hype for it is seeming to wear off the more people find out about it, and its taking for ever to arrive as well (not even on the site yet for cryin out loud)
as for overdrive units, i wouldnt put a gv in my car if you paid me...the thing is WAY too much money. Id rather put that money into an overdrive trans even if you have to cut the floor- its just a dart, not a numbers matching hemi cuda, so thers not much to cry about...id go with a stick, but if i was going auto the 4l80 and 200r4 seem like nice choices...id stay away from 4l60's (700r4) since every chevy guy i talk to hates those things with their lives in terms of power handling