Full shock/spring upgrade is planned, but needs saving for. Although trying to find someone to do a full set of Poly bushes is killing me.
and yes, I know the strut brace is more of a styling addition, but I like it
I used to do a bit of saloon racing in the U.S. and all my race cars had hard poly suspension bushings. But I would never put them on a street car; noisy, harsh, and really horrible for every day use.
If you're going to do a LOT of track days, perhaps you might consider poly bushings if they aren't too hard, but even then I'm not sure I would recommend it.
Of course, I'm an old fart now and I suspect back in my 20's (a long time ago) I might have had a different point of view. In my 20's I used to thrash my 911 around the streets of San Diego with un-muffled exhaust pipes while acting like a complete fool.
As for high performance dampers; yes they're better than standard especially when matched with stiffer springs. However, for street use, unless you drive like an idiot, I don't think they're worth the money. I'm very happy with just the Eibach springs on my Spider, but I don't do track days anymore.
Of course, if you've got lots of money and you're itching to spend it on your car, go for it. Me? I could afford shocks, brakes, etc., but I can't justify the expense for what would be a very minor gain for me. Springs were well worth the minimum cost though and I'd recommend them for just about anyone.
By the way, the so called strut brace doesn't do anything for a Spider either (except it looks nice).