Manual to Auto, Killswitch, Drive shaft

[wayzhack]

Background Info:
So I currently have an mk3 (1988) toyota supra turbo shell, which was designed for 5spd. It does not have the transmission or engine. My plan is to buy a JDM 7mgte engine and auto tranny (for $1600 shipped), and drop it in. The reason I'm going auto (sad I know...) is because it will cost me much less, believe me I have already done the math. I'm pretty clueless about cars, but I'm trying my best to learn and complete my Supra project.

Here are my questions:

1. I only have one section of the drive shaft, so I'm going to get a new one. I know little to nothing about drive ("propeller") shafts.
A) Should I try to buy a 2 piece, or is it worth the extra money to buy a
1 piece?
B) Also, is there any specific drive shaft I will need to get for an auto transmission?

2. Will I need anything else to swap the new auto tranny and engine into the 5spd shell besides a new drive shaft? Someone told me that the 5spd ECU on my car would work on an Auto tranny... is this true?

3. Would it be possible to wire the clutch safety switch (the button under the clutch which needs to be depressed for the engine to turn on) and remove the button, but use the same lines to make an engine kill switch?