A Janome 9700. That way you get a great machine, great service, and it has a ton of sewing stitches AND embroidery for 4x4 and 5x7 hoops. It would be versatile for everythingl.
I have a Tin Lizzie Longarm, Janome 9500, Janome 1600 P-QC, and some oldies I have around collecting dust. z:)
Also consider what brand to get by finding the nearest dealer or repair center.