I'm really surprised that your 630 can't handle the job. They've got a heavier dc motor and are chain-driven. "Check hook system" usually means there's a thread tangle under the feed dogs or tangled in the hook. Or there may be something tangled in the take-up lever. Those are all things you can take care of yourself. Rotary hooks often get thread tangles. If you remove the needle plate, you can turn the hand wheel and look in to see if there's a thread tangle. I use a Havel's seam ripper and tweezers to get the thread out.
An old Kenmore is always great for heavy stuff. I find them every-once-in-a-while at the thrift store for $10 - $25. But they usually need a serious service. You want one with the feed dogs with teeth, not XXX cut into them--they just feed better.
Good Luck!