You sir are going to ruin your VC if you try e-brake turns... this isnt a front wheel drive... Try focussing on developing your suspension first.
If you want more oversteer, try getting solid poly-mount subframe bushings, solid diff mount, and stiffer suspension bushings in the rear and maybe some coilovers. This will help to reduce the body roll in the back and help to push a more even weight distribution. Keep in mind, the torsen LSD that came factory in the ST205 and in RC ST185s is not that strong. They have a fun habit of exploding in cars over 300ftlbs... Look at getting a clutch type LSD if you want something that can tolerate more torque.
If you want to durifteroo then you bought the wrong car...