IMO if you plan on keeping the car a DD and are not doing the K member swap due to needed extra clearance or racing, keep the stock K member. You can always paint or powder coat it.
If you do decide to swap out the stocker, I 2nd the recommendation. MM or nothing. Do it right the first time and avoid parts that don't fit, poor alignment, crappy welds, and cheap copies. Do you plan on keeping the stock A arms, struts, shocks? That will also play a role in deciding.