THX Rear Speaker with Magnepan?

Hi there, I have 1.6 in front and MGCC1 for center so far so good...but I need a rear channel speaker (THX dipole would be a plus) ... Any suggestions ? My first intention was to purchase the magnepan SS1 but they are not available anywhere (surprise!) and when I called Magenpan I have been told that the production of the SS1 as been alted for the moment !? Magnepan is REALLY great speaker but the Magnepan corporation as to wake up and smell the coffee, it is rediculous to introduce a product like the SS1 and just stoping production to fill out order for the other model (keep in mind the SS1 is the only surround speaker they have !). Anyway if you guys have any recomendation feel free to share it with me. Cheer Alex