I would just get an Eagle in .40. You can use it for both IPSC and IDPA. A .40 can be made to shoot softer than a 9mm. You don't have the feeding issues with a .40 that can be a problem with a 9mm. I sold a STI, that I built, a couple of months ago. Brownells carries a SS magwell that will fit into the IDPA box. If you need more weight up front for Limited just add a tungsden guide rod. I also added a regular steel main spring housing from a 1911 for additional weight.