The lower A arms pointing up give a very high roll center. According to all the experts and the engineering books.
     But.   The fast cars are  under the flat arm height.  Even if the A arms are set  to point down alittle at rest, the arm moves  as soon as you turn the car hard and the arm then points up anyway.
    I was not clear if the car is a street car or race car 
     As for the street A 1 car; Lower the car until the arms are just above flat. set the  camber and toe. you will need some real shox (Bilstein sport ? ) and springs( 250 to 350) to keep it from hitting bottom. use a strut brace. Every thing is a compromise the ride will get  harsher . if it bottoms too much . or you live in the north, keep it up some. The strut bearing and fenders take a lot of abuse when done this way.  Try the  collasped rubber strut mounts with springs up to  about 300#. over that spring rate, the strut bearing deflects more than the spring, and becomes the  spring.  
  race springs are  maybe 450 front /300 rear with a rear sway bar/open diff. (I use less) 
     
    You pick up a lot of driveability/turn in with some rear toe out(8-10 mm per side)  and about 1* camber . 
 it allows a lot softer rear spring and wont spin as often.
    5- 6mm is about zero scrub for 1degree camber.  
 WFM. MM
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