You can put the totems into a castsequence just like any other spell.

Just as an example, you could do something like:
/castsequence reset=combat Searing Totem, Lightning Bolt, Lightning Bolt, Lightning Bolt, Lightning Bolt, Lightning Bolt, Lightning Bolt, Lightning Bolt, Lightning Bolt, Lightning Bolt, Lightning Bolt

Use that instead of your Lightning Bolt spell and it will always drop your searing totem first.