Summoner spell for supports

I think Riot made a great job with smite. Junglers must choose that spell, but they get various advantages (unique items, extra gold, extra xp, etc.) to keep up with the game. And you can evolve the smite by buying a 450 gold item based on your playstyle, so forcing this choice is not restriction.

Why a similar spell cannot be added for supports? It could have a great disadvantage (e.g. -75% gold for killing minions), but you could get advantages. The problem with supports that they have less gold (this is ok), but they have to pay the same price for stuff. Some unique items (similar to machete) which is only available to those who picks this spell could help a lot.

Even champion statistics could be changed when you pick this spell. Supports must be a threat - generally weak, but they can change the game with a few well aimed spells. When you play a non-support role you need more survivability at the expense of lower game impact.

What do you think?