For that car I woudl look at quickor suspension quickor.com as they have all the pieces that you may need including the rebuilt a-arms shoudl you require them..
Bringing the suspension down will affect roll center and the heavier bars will also tighten things up..
I would incline for 700 lb springs up front and about 200 in the rear and a rear bar as well..once the car is done a trip to an atocross meet or something like that would be in order to see that the front rear roll bias is in order and if some more tuning is necessary to get the push or loose out of the car..oversteer/understeer..Might have to do a spring change to get it right for your driving style..
I am a bit of a bug on having a car that goes around corners as well as being fast...
Try stockcarproducts.com for suspenion parts as well..
I have tried most all of it and now do what is known to work..