Good place to start is to find out what parts are needed.
Personally not a fan of air(suspension) because it would prolly ruin the handling of the car, plus you have to plan for where to put the aircompressor and airlines.
You would most likely be looking at coilovers rather than just lowering springs.
Might need camber arms replaced so camber can be adjusted more to your liking.
Unless you know how to roll arches, that will most likely be a bodyshop job
Also consider that you may lose some ride comfort, as the car sits lower it will have less clearance to "bounce" thus suspension will be stiffer to counteract and with bigger wheels come lower profile tyres, which will improve handling a little due to less sidewall flex, but at the same time feel a little harder.
So, all in all if you wanted to get this all done you would need to visit a bodyshop and a workshop.
So consider labour and parts and prolly little return from a couple of grand.