[quote name='coldwine']If I buy now, can I download 3-4 months from now?
My current machine won't play it, want to buy something considerably better over the next few months.[/QUOTE]
You could download it ten years from now if you want. You could download it today, install steam on the new machine, and then copy your steam folder over from the old computer and all your steam games will still work without having to be installed again.