I would do the subframe connectors for the piece of mind that you will not twist anything- I did the subframes first, and the springs second both were big improvements over stock !
You maybe could save up a little more and really get a bang for your bucks with some adjustable shocks.
The KYBs are VERY good (4 way struts and 8 way shocks) and are available for as little as $350/set. Eibach Pros can be had for $175-ish.
THAT combination will give you unlimited entertainment valuable as it makes the handling VERY tuneable. From drag racing to road racing set-ups, between the shock settings and tire pressures, nearly ANY handling quirk you could ever want is available.
BTW I have this combo and each and every shock setting step is felt immediately. These aren't Illuminas, but they certainly are very good shocks for a street/road car.
Shocks and springs. They make much more difference to handling than the SFCs, no question. Effect of SFCs on handling is very mild in my opinion, it tightens up the vert a lot but made no difference in handling compared to lowering.