They won't 'break' anything. However, if you are going with stock springs/shocks, and the Eibach setup, really think about installing both front and rear bars. The rear bar alone could lead to some dangerous handling traits, in my opinion.
2003 Ford Focus ZX3 2.3l N/A = 221 HP, 162 ft-lbs, email@example.comMPH - SOLD
2006 Ford Fusion 2.3l Turbo = 244HP, 247ft-lbs
2014 Ford Fiesta 1.0; Turbo