And a new fitting for the front block. The stock front block uses backasswards "proprietary" threading, and you'll need to get something like this
to make it for the correct threads.
If you get a new regulator, then the stock ASA/reg might have enough obstructions when not used as a regulator to restrict the flow to the new regulator, thus starving your marker and killing recharge rates at high ROF's. Macroline is merely a preference choice, but keep in mind that you will need to get a new hose anyways (the threading for the stock hose is metric and the threading for everything else is NPT). HobbyHorse here and on PBNation can hook you up with a good deal on some macro, I believe it was like $12 or something for a complete kit after his flat rate shipping. Here's a link to his website