what a howell bottom end kit is, what it does.
not sure

-what a final drive mod is, what it does
the final drive mod takes the final drive gears from the stratus transmission. They are "teethed" different than the final drive gears we have. Supposed to give you better acceleration. Why they wern't put in our cars to begin with I dunno.

-how a shift kit works.
A shift kit "reprograms" your transmission for better shifts. They are quicker and snappier. This is good, cause you know how long it takes our tranny to shift gears.

-has anyone used a trans brake, where did they find it.
no clue =)

-what does a tq converter do.
a torque converter is more or less your clutch and clutch pedal. When you come to a stop with a 5sp you push the pedal in to disengage the clutch to your engine doesnt die. Well an automatic doesnt have a clutch we have a torque converter. Among other things but specifically to your question, it keeps the engine running by spinning at not just stopping when the engine stops. Check out howstuffworks.com. They have a really good explanation of it.

-what other parts will i need.
a spare transmission=).