Welcome from NJ. Very cute rag quilt and lucky you to have your mom's featherweight! Definitely a great machine.
Yes, you'll get lots of suggestions here regarding machines. I agree with buying from a local dealer vs Amazon. Not even necessarily for classes but for local service when the need arises. With the budget you have in mind, you might want to consider a higher-end used machine from a local dealer. Many times these will even come with some limited warranty. You have a great back-up and piecing machine with the featherweight.
I would suggest making up a list for yourself of all of your 'wants' and 'needs'. When I was shopping a number of years ago, one of my 'needs' was the needle up/down feature. Didn't care about bunches of stitches but ended up getting them anyhow due to other 'needs' on my list. I have a computerized Viking Platinum and love it. Have not had an hours worth of difficulty with it. I do next to no machine quilting. I'm a hand quilter and only machine quilt those charity quilts or craft projects that demand it. And the machine handles it just fine.
And definitely take your own practice pieces - both piecing fabrics and a quilting sandwich - of fabrics you typically sew. I do a reasonable amount of home dec sewing as well. My machine will handle from sheer to upholstery fabrics and everything in between. And the best feature is auto tension! I don't have to change any tension settings - just pick a fabric type from the menu and bingo - it's all set.
Happy quilting!