I purchased a very old Makita chop of saw to cut the ali for my last machine but its so old I cant even find replacement blades.

I now need a saw that will cut the 100x100 steel box section for my new machine plus a bunch of other things but not sure what to go for?

what are the abrasive disk type saw's like? accurate enuff to build a machine with?

it would be nice to have one saw that does booth ali and steel but is it better to have two separate ones instead?