What a nice hubby you are. Is it important that she gets the machine as a gift? Just wondering because I would prefer to pick my own machine. Maybe you could find out what features are important to her. I can tell you that for quilts my must haves are needle up/down, needle position sideways, motor speed control, easy threader, LARGE THROAT, handle thick layers.
Is she going to keep the Singer for regular piecing? In that case you may consider a simple mechanical straight-stitch machine such as the Brother 1600, Pfaff 1200, Yuki 980 etc (they are all essentially the same machine). This machine has a large throat and it sews at 1500 to 1600 stitches a minute BUT it only goes forward or backwards.
My favorite brand is Baby Lock but I don't know what their prices are. Whichever one gets chosen, I'd want to take her for a test drive.