I like the 2004r better for gearing reasons, The 1st to 2cd drop in a 700 is too much, Its 3.07 first gear right to (i believe) 1.68 seconds gear, You need a good amount of power to keep moving efficiently.The gear drop in the 200 is now where near that,But on the other hand it give you an ultra low first gear. As far as durability, Either one can be built to with stand the power an average street car makes.
2004r brakeage= generally forward drum,some times input shaft
700r4= sun shells, They say forward drum(never seen it)and in my old camaro i broke everything from planets to splitting the output shaft in two!
I prefer the 3004r if built correclty
You might waht to have this moved to the tranny section
Hope this helps