Frank S and C-Bag , thank you guys for your advice and input. Clearly I need to sit down and work out some kinks. I just put together something that I had in my head on the spot, all i did was drill and bolt using some scrap, but You guys certainly have given me enough to work on in planning to obtain what I want.

And what I want is well because of mobility issues, I really want to be able to sit at a bench and cut some metal.I want to be able to just push/slide the work piece thru the blade. I work with pretty small pieces of Steel and aluminium, ranging from 2-4 mm and no bigger than 150 mm x 300 mm. It's all sheet off-cuts and the odd section or extrusion pieces that come by post so they're never going to be too big. I'm not going to be working on a lot of metal projects, but for ease of use i want to try and build something from the resources I have.
For now though, I think it's back to the drawing board. Again many thanks