The Brother machines are great and I agree with others have said about the Singers.
I have the CS6000i and love it for travel & classes but I don't feel it is heavy enough for what you want to do.
I would suggest you save up & wait til you could get maybe the Brother 1500 straight stitch only machine-a very heavy duty machine, great for FMQ & heavier fabrics.
The other choice would be some of the vintage machines that were top of their line in their day-some are still working wonders, check estate sales, dealers used machines, etc.