1/8" - don't suppose you'd know if it was cast or extruded would you?
For 1/8" material a jigsaw just won't work, it will crack as your cutting.
Circular saw, if it's extruded you're probably going to want to cover over (plywood works good) and clamp down the 'keep' side of your cut.
Table saw or router would be preferable. 1/8" is kinda finicky to cut - hand saws work well though
