warrenelec,
It is possible to set all the z coordinates to 0. I'll do a step by step. (1) Get desired iso view in modelspace (2) Type ucs and set it to "v" for view (3) Goto paperspace and create your solview by selecting options: a)ucs b)current c)view scale "1" (i usually use 1; though I don't think it matters to much as I end up scaling my isometric 2d drawing)
d) pick center e)specify viewport (just hit enter) f)choose corners of your viewport g)make a name h)hit enter to end command (4) Enter soldraw and select viewport in paperspace that you just created from solview (5) go back to modelspace and filter out the new layers created (yourname-vis, yourname-hid, yourname-dim) and use a cutclip (control x) and open a new drawing and pasteclip (control v).