Coil over conversion on 73 dart sport

I am considering doing a coil over front suspension conversion with rack and pinion steering on my 73 dart sport . I am running a 325 HP 340 hooked to a TCI 904 Auto. I am looking at the Magnum Force XRT. Was wondering if any one done one of these and what you think about it. Also are there any less expensive options out there, that come as a complete kit?