Yes, yes, yes to "get yourself to a large show and test drive as many machines as possible." AQS Daytona show is in February ... can you make that show? Honestly, I can't say enough about how important this is.
My experience: I did go to large shows and test drove many framed and sit down machines. I fell in love with the Innova machine, but having zero experience on a framed machine I couldn't justify the price not knowing if I would be good at it and if I would like it long-term. So I bought a used machine at a very reasonable price and I am now learning on that. In the mean time, I also bought a new sit down machine - and I certainly see me using both log-term. At this point, if I ONLY use the frame to baste large quilts I can still justify the expense of the framed machine.
Space is a consideration to the frame set up. If you don't have the space, stop looking. I made the mistake of setting my frame up at a remote location and I didn't use it enough. I've since moved and now my frame is upstairs. I am still in the process of getting my sewing room set up, but I hope to have everything operational in a few weeks.
Of course basting is an issue with the sit-down machines. I loathe basting which is the main reason I went shopping for a framed long-arm.
With regard to choosing a frame before you choose a machine, you might want to reconsider. Most of the machine companies will prefer that you use the frame they sell, and not all machines will work with all frames. I would concentrate on the machine first, then if there is a choice of frames for that machine and one of them is the Grace, then go for it. That is not to say the frame is not important, there are some frame features that buyers will consider a must (ie dead bar, lift system, etc). But you want to make sure the machine and frame work well together AND your dealer will still support the machine if you don't buy their frame. You don't want to have a problem and have the machine dealer blame the frame dealer, and visa-versa.
But again, get yourself to a large show (or many dealers) and test drive as many machines as you can. Keep a list of things you like and dislike, keep a list of features you have to have and could live without, keep a list of prices and dealer locations (it may or may not be important).
One last thing, after you have a list of machines and frames you like and dislike, shop the used machines. Often you can find a machine with more bells and whistles than you thought you could afford in a used machine.