Now that you've clarified that you're talking about a Miata (you weren't so clear about that fact in your initial post)...

Your springs are fine, or at least no worse than they were from the factory.

Your shocks are most likely junk. OE shocks get weak by 40k miles, are yours original? How many miles on the car? Get a set of Konis. KYB AGX if you're cheap.

If your Miata has high miles (being a 94, miles not even matter so much), you would likely see a lot of improvement from new control arm bushings.

Shocks are going to be the major thing controlling the body roll that you're complaining about. Miatas DO have a lot of body roll by design. Controlling it is good... but eliminating it altogether might not be as good as you think.

I wouldn't bother converting your Miata to another package. The "M" edition is mostly cosmetic and includes a lot of heavy power options and leather. None of the Miata spring rates are so different to really be worth changing for except for MAYBE the R model, but even then the difference is subtle.

Don't forget to get a good alignment! Not a generic tire store alignment, but a really good precise performance alignment.

Lastly, Miata.Net is your friend. There's a lot of good info out there in their Forum as well as the Garage section.