our cars are never going to ride like a miata, but you can make it a very fun car to drive with the correct suspension upgrades.
What are your plans with the car? weekend canyon carving? Occasional track duty?

you can use this as a rough guideline for upgrading your suspension depending on what your goals are. Keep in mind this is only for the suspension, I have not yet touched on all the other bits that will need to be upgraded as well. There are probably other options in these price points, but this will be my recommendation based on my local track crowd and general feedback from other drivers who owns or have owned these products.

I'm not going to go any higher than ohlins because if your budget is up there, you probably know what you're getting into.
>$2000 - ohlins R&T, probably the most popular dual purpose street/track suspension among the Z/G community for the serious drivers. KW V3 would also fall into this range, however most track folks who had V3's dislike the progressive springs and they're too soft for track duty.
$1500 to $2000 - HKS Hipermax IV SP/GT, cars running the SP consistently runs as fast as the folks with custom spring rate ohlins on the track. go with the GT if you want a more street friendly ride. Bilstein PSS10 is also a very street friendly system in this price range.
$1000 to $1500 - Fortune Auto 500 or Feal - well built suspension, options for custom rates and well matched dampers to springs. however, adjustment range on these begin getting weak. As in, full soft and full stiff isn't actually that huge of a difference.
<$1000 - Koni Yellow + H&R Sport springs, Bilstein PSS9, Tein Flex Z. You start trading adjustability for a lower price here, but are still getting good quality dampers and systems that are tested/tuned with shocks that are properly valved to match the springs they come with.

Hope this helps narrow things down a bit for you.