the NQS BBK is worth every penny. it's feels totally OEM and you can really feel the extra bite the brakes give. if i could do things again tho, i'd wait for a 2nd had 996TT kit to come up. it's basically the same as the NQS BBK, but uses the 996 Turbo calipers and 350mm discs instead. a 2nd hand kit will cost the same as a new NQS.
suspension wise it depends on what you want from it. do you want/need adjustibility? if you do it is widely believed that you opt for some of the more expensive kits, KW V2 etc. if your budget is lower or you don't wish to fiddle then most recommend the Bilstein B12 kit. that said, i have Weitec Hicon GT coilovers and have been very happy with them.
i would recommend if you're having your suspension lowered to get a Whiteline Anti Lift Kit (WALK) fitted at the same time. the reason for this is that it will save you having to get the car realigned a 2nd time when you inevitably decide you want one in a few months time.
happy modding!