Coilovers on a budget?

wstar

I've already got swaybars on my car, one of my earliest mods. The swaybar upgrade is really awesome when it comes to keeping the car flatter in a turn, it's a huge win. Shock/Spring upgrades are for a different purpose though. The primary problem I see with my current (factory) suspension right now is it's too soft/bouncy during and just after braking, leading to a bit of a "porpoising" effect. I imagine just about any entry level quality adjustable coilover setup will let me tune that out to some degree. I don't really even want to drop the car at this time, at least not aggressively. Maybe half an inch.

The big question marks to me are:
1) External Reservoir? Seems like the primary purpose is fluid cooling for extended running? I can't seem to find a good analysis on when you need this, but I'm inclined to think 30-minute track sessions are fine without it.
2) Spring rates?

From what I've read (and I think I'm still failing to comprehend some things), it seems it's all about Spring Rates in the end. It seems like for a given car config (total weight, distribution, geometry) there's probably a certain spring rate ratio that's ideal, and some room for variance based on how stiff you want the ride to be. And then the shock adjustments for bound/rebound really just have just one ideal setting that's matched to the springs and your car's weight (although maybe it's nice to turn them softer for a street cruise). Picking the spring rates is something I haven't seen much data on though. Is there some standard rules of thumb based on corner weights, etc?

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