I'm shocked that the steel is coming in over 500. I could swear I got mine for about 200 not that long ago. Metal Supermarket, new cut to order. Though I did just have a few cuts done, I had a bandsaw at that point, so I just needed manageable sizes. I don't think I'm 500 all in with a good deal on a 3ph motor, wheels, and VFD, though I did go cheap on the VFD.
The square tool is what I use for about 90% of my turning. If a different type is needed for your project, I can probably make it. Just trying to get you going so you can make what you need to while you decide on the grinder setup you want to use. I'd hate to see someone settle on a grinder they don't want just for lack of a lathe tool.