I used the Rockler lift - the sewing machine shop was willing to order the same one for over $200.
One of the things that turned out to be important, that I didn't think would be, is that there are three positions, not just two.
1. All the way down (to close the cabinet). Push down an inch and the sewing machine comes up to
2. A position even with the sewing surface. Some of the store cabinets have a plastic piece that bridges the inch or so gap between the machine and the table top, but Jenny doesn't miss it - no problem. From here you can push all the way down (to a click) at position 1, or push down an inch and the sewing machine rises up to
3. tabletop height, for use with some of the options such as free arm or embroidery. Push down to either positions 1 or 2.
Needless to say, position 2 is adjustable (with tools) for a specific machine.
The unit closes up pretty small (don't look at the wood - I didn't know how it would come out, so I used up all the old ugly walnut in the shop. It came out good, so now I have something with ugly wood in our house.) The drawers remain accessible when the unit is closed (good).
The front and left side are a rigid unit, L shaped, that opens to become the support for the work area (the top flips open). Be sure to use double pin hinges for the top (also available from Rockler). Unlike the store-made cabinets, I put storage at the bottom of the doors (should have been taller for cutting boards, etc.). Note the machine is at the middle position (2) in this picture.
The sewing machine comes to the upper position (3), in this case for free-arm use. Leave an opening or something in the side of the elevator platform for the power cord (so the machine can be left plugged in). Note that I got a shallow drawer at the front (can't be deep - that is where the machine is), but Jenny loves that center drawer. See the upper right drawer (you will see it again below), and one of the other drawers is open. In the background is an old lingerie chest, which Jenny uses for project storage.
Note that the right part of the top flips open, like an arm, using more of those double pin hinges, and is supported by the top drawer. This seemed like a really neat idea, but Jenny never uses it. (That part of the top accumulates junque before it gets opened, so that may be the reason she never bothers to open it).
Of course, if the top arm is supported by the top drawer, how do you get into the drawer? This was a fair amount of work... (and since she doesn't open the arm, well... you know), but the drawer that opened to the front, can also be opened from the side.
Only a woodworker would care how that works. The top drawer only pulls half way out, and is very stiff (almost no vertical play). When the lid flips open, the outside is now down against the top of the drawer. So far, ok. But a lot of fiddling made the drawer stiff with a hole in it's side, and the "inner drawer" can be accessed normally, or from the side.
Enjoy your project!