I have several brands of thread for my longarm, but I find myself using Metro thread that I purchased from MetroEmb.com most often. It's a 40 wt. high tensile poly thread with a beautiful sheen, a huge assortment of colors, and the price is great. I'm also going to try the Sigma thread from the same company. I also use cotton and poly thread from Connecting Threads and Superior.
In your case, since you are using a vintage machine, have you tried sewing with the machine off the frame to see whether the problem occurs then, or only when the machine is on the frame? If it's only with the machine on the frame, I would agree with Geri B that you might need to slow down. The speed of the needle with the domestic machine is not very fast, and the needle may be deflected by the quilt causing breakage of the thread, and occasionally breakage of the needle as well. Using a larger needle might also help with that.