I agree with Sean. If you are only going to be welding 1/4 AL every one in a while then adding a Helium bottle and running a mix should suit you just fine. If you however find yourself doing thicker material more often then you would need to upgrade to a larger unit. I was also thinking about getting the 185 but instead opted for the 200dx. I figured that since the 185 didn't come with a foot pedal, I gain pulse and a few extra amps for only $300 or so more I went with the 200dx. One thing I hate is buying something and having to upgrade soon thereafter. Even now I have a dedicated 75/25 Argon/Helium mix for when I weld anodized pipe. I only do maybe a few things here and there so far as repairs but it works fine.