The bulk of my mods are listed in my signature. It's a stock long block with bolt ons. 6lb lower is what is used in that video.
Tremec price-fixes the cost of new transmissions, so you get the same price no matter who you buy it from (in theory). I think the T56 Magnum is going for just over $3k now. I'd have to do some number crunching to come up with a total. After all the incidentals, I think you'd end up a little over $5000 total. Probably not more than $6000. I also haven't had my passenger seat cut down yet.
Time-wise, I've got a lot in it. Being the first to put in this transmission and use these hydraulics, there was a lot of "figuring" time. I also built a completely custom shifter mechanism. It was about a 6 month calendar process. I worked on it pretty passively, and had a lot of other stuff going on in my life at the same time. With all the parts on hand, copying my build, I think a person could get to the point of a test drive within a weekend or two.