I would check out some of the different sewing tables on line and go from there. My DH made me a desk top. It's just a top and is 5'x 2'. I have a file cabinet at each end. it is very sturdy. You state you have "about" 6'x 2.5' to work with. Is that total space size for the table top or total space for it to be placed in? Either way, that's a lot of space to be able to sew/craft on. By making just a top and using a couple cabinets as the bases, you would be creating extra storage space and it would be easy to move/transport. Just for the heck of it, one day I brought my Singer portable in to see if it jiggled or not. It was great and you can adjust the height. Of course I don't have a hole in it but that shouldn't be a problem.