I would recomend you the Brother PQ1500 which makes only the straight stitch and well done stippling but has an extra space in the throat (for bigger projects) comes with extensive table (which is very useful) and walking foot and many other feet......
I am very happy with this machine.....
I am making the decorative stitching on a smaller machine....
Yes...sometimes I wish I had a machine that would do all of these thing together but they are more expensive and there are no machine sevices where I live.....
My wilder dream: is a real long arm quilting machine...
The most important thing for me is the wide space in the throat....
Good luck