There are plenty of conventional alfalfa varieties available that will have a high disease index, along with a very winterhardy rating  for your area.   Just like other no-til scenarios, if using last years'  wheat stubble to plant into, just need to start with a clean seedbed.  Take care of any perennials the fall before and maybe hitting it with a shot of Rup before planting.  Select and Poast Plus work well on grasses in alfalfa and Raptor works well on grasses and reasonably well on broadleaves in alfalfa.  

If you put down plenty of seed and get an excellent catch, that is the best defense against weeds.  

If you are selling baled alfalfa, some customers will view RR alfalfa negatively.