As far as the ER-14 goes. To lower the ride height you can either use Xray XB4 springs or AE Big Bore springs. The Xray springs are shorter but if you still want lower ride heights even with stock springs (less than 19mm) then you need AE B5M spring perches and ball ends. AS91448 and AS91310 are the correct part numbers. You will need to space the rod end away from the wishbone a little as the lowest perch does hit the wishbone on full extension.

The car has way too much roll in it as standard and almost no negative camber gain. The biggest changes I made to effect the balance on the car were:

Lower the front turnbuckle to the outside lower hole on the front tower. The ball end will rub against the bulkhead a little, just remove a little material from the bulkhead. You can then add washers under the ball stud on the hub to add more camber gain at the front which will give it alot more bite should you need it.

Move the inner rear ballstud from the normal mounting holes down to the shock tower mounting hole. I used extra long Schumacher ball studs and rod ends. U3299, it is a shorter rod end so you might need a longer turnbuckle if memory serves (will check if needed). Also move the rear hub hinge pin to the inside mounting hole on the wishbone.