what to do?

I have ordered all the books on doing this.
My biggest worry is that I will screw up and then it will really cost me, yet I can't learn if I don't do it myself.The longer I think maybe the more relaxed the wife will get lol.
btw what do you guys think of the combo for a weekend fun car?
Eventually I will find an 8 3/4 and put it in with 3.91 or 4.10 gears depending on which I find a better deal on.I am also shopping for a tq converter in the 1800-2400 range.
Thx for your opinions and you guys are where I am at 50/50