Neesie,
I owned an embroidery machine before that had the 4x4. For me it was a great learning tool however think of this too...on the 5 x 7 you can do a small amount of embroidery patterns on the same hoop such as quilt labels and applique embroidery. Just a thought. I mostly use my 5x7 or my 6x6. I use the 60 wt. bobbin thread and for FSL I use the same color in the bobbin. Like Quilty Louise I too am a deep Floriani thread fan and at first I used Sulky since they always had great sales on them at Joann's, 50%! Everything will be a "trial by fire" and once you get the hang of it there is not stopping you LOL!