[Mulder25]

I have a couple additions planned for my new car, a 2001 Toyota Corolla.
The first is a kill switch to shut off the fuel injectors, allowing me to coast in neutral, thus eliminating engine drag. I have a few reservations about this process and was hoping that someone could clear things up a bit:
I read that about 0.001% of cars in production have DFCO(deceleration fuel cut off - shuts off fuel injectors while coasting above a set speed). Is this true? Am i extremely lucky to have one that does, or is this statistic/my testing(scanguage reads 9999MPG when pedal is released) faulty?
If i do indeed have DFCO, then it doesnt make much sense to install a cut-off. For the rare instances when i will be coasting(a 3 mile down-hill, about 4 times a week), i can just deal with the extra hassle of using the key.
I would like to install a cruise control/hand throttle device. Basically, i know what the most efficient throttle position is, but i hate the hassle of using my foot to maintain it. I want to install a cruise control device that operates with several buttons, these would include a way to set the throttle position, a momentary push button to increase by 2, and one to increase by 4. In addition, one to decrease by two. For example, i could set it at 17, start going downhill with a fair-grade incline after, increase to 21 temporarily, then reduce to 19 right as i hit the hill. I would speed up to 72-75, then top the hill at 58-60.
Any thoughts on this? I would like to make it automatic, basically, set a permanent set of parameters on how far to deviate from the set speed, a maximum and minimum throttle position, and if possible a way to detect the current incline in degrees, pos./neg. of 90. I have very little programming knowledge - i tried to learn it, but the best i can do is a simple script in C++. Most of the interface needs to be mechanical/electrical, and not digital, or have someone else write the script, and give me a circuit diagram.
Thank you for any input you provide. All comments are welcome.