I LOVE my Supreme Slider! Whenever I have FMQ or machine applique to do my Slider comes out. I just wish I could get a bigger one to completely cover my Sew-EZ table. They are a bit spendy, but worth every penny.
I have a small external flexable light for my sewing machine. I found that the light in the machine is just not bright enough (especially when using black thread on black fabric). It is removable for when I am doing FMQ.
As for the Sew Steady - I am not familiar with that one. I have a Sew-EZ, again a bit spendy, but perfect for portability. I am sewing in my dining room and have my machine in the Sew-EZ so I can still use the table as a dinner table. It goes with me to classes and when I travel (and have enought time to sew).
I love tools and gadgets and if you are like me, Whatever you decide to get, you will enjoy. Have Fun.