I found this online-
QUOTE-
I have a Janome 1600P-DB that I use on a Little Gracie II quilting frame. The machine does NOT have to be used with a frame - you can use it as a regular sewing/quilting machine. It has a 9" throat and a max speed of 1600 stitches per minute (the fastest home machine available). This is a very basic machine. It's essentially a straight stitch industrial sewing machine, no fancy stitches. Janome has three 1600P machines - the standard 1600P, the 1600P-DB, and the 1600P-DBX. The "DB" indicates that it uses a special type of needle, and they are a bit more difficult to find, but if you buy in bulk it isn't an issue. The 1600P and the 1600P-DBX have thread cutters and the 1600P has an automatic threader. The 1600P-DB is around $700 and the 1600P and 1600P-DBX are around $800.
The Janome 1600P is essentially the same machine as the Pfaff Grand Quilter and the Viking Mega Quilter. All are made by the same company, and all are similarly priced. Except the external appearance, they're the same machine.
Juki and Brother both have 9" throat machines, and both have a max speed of 1500 stitches per minutes. They're comparable in price to the others.-END QUOTE
I have the Janome 6500 and the Janome 1600P is in essence the same machine but a straight stitch so no fancies. the automatic thread cutter and knee lifter are very important to me.
Another well trusted machine is the Juki.