im not an expert like zip, but id imagine using something like this:
/equip Weapon 1
/equip Weapon 2
would work ok. my understanding of the macro system is that it checks each line of the statement and then sees if its "true" or "false". so if you have weapon 1 equipped and you push the macro, then the first line comes up as "true" and the second as false. the macro then makes it so the second line becomes "true". then if you push it again, the first line is now false, so the macro makes it so it becomes true (and stops it there).
course, i could be wrong (i probably am), so in that case you would probably need a shift/alt/ctrl modifier button in there, meaning its one macro but would require you to push a second button along with it half the time.