'05 Allroad 2.7T (petrol) suspension issue...?

Hi. I'm new to this forum and needed some help.
I have '05 allroad (I'm in the States in eastcoast) and would like to see if I can make my suspension a bit firmer.
I have the stock pneumatic adjustable suspension and was told that it can't be modified to be different setting.
Another thought was to switch to lower profile tire - I have stock 225/55R/17 and changed my tires late-last year to Bridgestone Turanza LS-V.
I don't know if its the tires or the suspension that make my ride a little bit "bouncy soft"... maybe that's the tendency of the air suspension?...
Does anyone have experience or suggestion of how to stiffen the ride? Would switching to lower profile tire/wheels help? - what brand/model tires can you recommend (other than the terrible Pirelli P6)?
I don't want to lower my car though.
Any suggestion would be appreciated

I believe the Allroad has air suspension, not the coil-spring type.
Isn't the shock you mentioned applicable to typical coil-spring?
Or can you tell me little more details?
Thanks.

Since it seems to be hard to mass up with the pnuematic adjustable suspension unlike conventional coil springs, I was told that one of the easier thing that can make Allroad's ride firmer is to upgrade the anti-roll bar (sway bar).
Has anyone have any experience on Allroad?
Does anybody know the size of the stock anti-roll bar (front/rear) and what would be a good size for upgrade ("Hotchkis" has a product with 35mm front + 24mm rear for about US$400)?
Can you really feel the difference when you drive?
Any suggestion would be appreciated.