Suspension upgrade Qs for '65 coupe

[DeltaMustang65]

I'm planning on getting started up front on monday, since I work this weekend. Gotta admit I'm a little worried about the stiffness of the springs. The back is very firm, and the leafs are rated at 195 lbs I believe. The coils are over twice that, and yes the front is heavier but I can't help but wonder if the car is going to be balanced and if it's going to get all skittish on the crummy streets here in Stockton.

Also, does it make a difference if I do the Shelby drop first? Should I remove both coils and drop both sides at the same time and then install all the new parts, or should I do one side at a time? As I've said before, I've never done any of this before. If you guys can help me avoid any pitfalls, that would be great. Thanks.