I have been FMQ for many years on my Bernina. I am still able to quilt a king size with it. Last year my friend was selling her juki TL98e for $400. I bought it from her. It is a great machine. I call it a working horse. And for that reason i got it. I didnt want to over work my bernina. Lol...
If all you will need is straight stitching i would highly recommed the juki. Make sure it comes with the free motion foot. It also has needle down option, knee down leveler, and one of my favorite is the scissor. So when you quilting in the middle of the huge quilt, you dont have to dig down looking to cut the bobbin thread. Overall, for a simple machine it has many basic option that you will need and use. Oh did i mention speed adjustment... True and true it is a working horse.