I recommend rubber bushings for a good daily driver. Polyurethane are good for race but tend to squeak and are somewhat rougher in terms of ride quality, hence why they don't make for good everyday drivers.
FieroStore sells them as well as almost every other part you will need.
For springs if you want a kit then I recommend
West Coast Fiero. Otherwise you can make a kit yourself from collecting parts.
Also almost every question you will have has been asked and explained, use the search function on here and you will get an answer instantly!
EDIT: Sorry I'm not sure about where to get drop spindles, and I am not exactly sure of their advantage over shorter springs either. I recommend shorter stiffer springs.
[This message has been edited by DaytonTD (edited 08-05-2013).]