I´m also a bit disappointed about rear drum-brakes, but these are very easily updated later if you want!
How much you´re going to lower your car? I was thinking if you can move your front control-arms upwards enough if your car is going to be very low? I meen it´s not good having inner end of control-arm lower than the wheel-end of it when car is fully loaded with driver etc...
I think it is good idea to make some reinforcements into 03´s chassis front as it´s usually very rusted and weak... Nice job and patience for this kind of things!
Car is very nice! (altough I don´t like the curved windscreen so much) I´m waiting when we can see it painted...?!