Welcome!! I have a SX3 as well and used the cncfusion deluxe kit and am quite happy with it so far. One could argue the cost of the kit but for me it was worth every penny.
You can also do it a little cheaper by making your own conversion, did I read in another thread you have the g0602 as well?
If so you could turn your own ballscrews and use the mill to make the conversion parts for the mill.
Have you seen Creavive Reamer's site?
As far as some advice I would spend a fair bit of time re-fitting the gibs and lapping the ways for smooth reliable operation.
Here is a link to My build.