I was on another forum asking about ways to make my bike handle better (aside from improving skill, of course) & everyone suggested a Katana rear shock, firmer fork springs, & a heavier fork oil. Can anyone give me a rundown on this? I have a '96 E, all stock as far as drivetrain & suspension goes, & I weigh roughly 150-160lbs.

1) Is there any particular year Katana shock I need or should I just look for the best condition I can find? I've concluded that ebay is my friend for this.
2) What spec fork springs should I be looking for given my weight?
3) Someone told me I want straight rate springs if I'm an aggressive driver, progressive if not or if I commute. I do commute, but I also drive quite aggressively. Would straight rate springs be such a bad option with my bike as a daily driver?
4) Where can I find springs for a reasonable price? I'm hoping for a ball park of no more than $200 on parts alone.

1.) Check the wiki. And the  Buddha may have what you need.
2.) http://www.sonicsprings.com/catalog/calculate_spring_rate.php
3.) I have heard that straight rate springs are best. But I have progressive springs in my katana forks an am quite happy. But I don't ride very aggressively.
4.) looks like front springs will fit your budget. Maybe the rear shock, too.

I have a katana rear shock I'll happily part with if you're interested.