This would be epic, mind if I post some ideas?
Summoner Fortify
Causes the target allied tower to block the next 4 (+1 per level) champion basic attacks and 12 (+2 per level) minion basic attacks that could damage it. Shield lasts for a maximum of 10 seconds. While the shield is active, the tower gains 35% attack speed.
Range: 5750
Cool Down: 240 seconds
Champions it can benefit:
Safe/Farm Lane Champions

Summoner Golden Age
Increases your passive gold per second by 150% for 15 seconds. Is reduced down to a 15% boost for 5 seconds after taking damage. Once it runs out, you do not gain any gold per second for 4 seconds.
Cool Down: 210 seconds
Champions it can benefit:
Hyper Carries

Summoner Disrupt
Interrupts channels and dashes on the target champion and cause their cool downs to be frozen for 1.5 seconds.
Range: 900
Cool Down: 145 seconds
Champions it can benefit:
All Damage/No CC Champions

Summoner Mechanic
Heals the target allied tower for 25 (+35% missing health) health instantly. Multiple Summoner Mechanics can be used on the same turret, but Summoner Mechanics used after the first are reduced to 25% effectiveness from the last Summoner Mechanic meaning the first would heal for 25 (+35% missing health), then 6.25 (+8.75% missing health), and then 1.5 (+2.18% missing health). This debuff lasts for a duration equal to the cool down of the Summoner Mechanic first used on the turret while it was not already debuffed to other Summoner Mechanics.
Range: 750
Cool Down: 250 seconds
Champions it can benefit:
ALL CHAMPIONS with a few standing out:

Summoner Recruit
Non-epic monsters that have been killed within the last 12 seconds can be revived to push down the target lane. Monsters are revived at the champion's current position. Monsters have 80% (+3% per level) of their maximum health and 85 (+4% per level) of their attack damage and attack speed. Towers will try and kill these targets after champions, but before minions. Recruited monsters grant 5 gold, but no experience.
This spell can replace Smite to buy Hunter's Machete and it's upgrades to become 4 different upgraded Recruits. If the champion has both Smite and Recruit, both will be upgraded. No matter what upgrade is chosen, recruited monsters health will be increased to 80% (+4% per level).
Oppressive Minions: The equivalent to Chilling Smite. Causes recruited monsters to have their basic attacks slow the attack speed of enemy units and towers they hit by 30% for 2 seconds. Enemy champions only have their attack speed slowed by 20% for 1.5 seconds.
Destructive Minions: The equivalent of Blasting Smite. Causes recruited monsters to have their basic attacks deal 33% splash damage around their target.
Rogue Minions: The equivalent of Scavenging Smite. Causes recruited monsters to be able to be released into the target section of the enemy's jungle. When an enemy enters that section of their jungle, the monsters will charge at the target with a 5% movement speed boost and attack them. If a monster is told to go into the enemy jungle, they lose 66% of their armor and magic resist.
War Minions: The equivalent of Challenging Smite. Causes recruited monsters to have 25% increased movement speed and prioritize enemy champions instead of minions. Their basic attacks deal 4% (+1% per level) bonus damage to enemy champions as well.
Range: Global (targeting which lane/jungle section)
Cool Down: 260 seconds
Champions it can benefit:
Fast Camp Clear Speed Junglers

Summoner Destruction
Deals 180 (+20 per level) true damage to the target tower instantly. This is reduced to 90 (+10 per level) if no minions or Zz'Rot Portal minions are within range of the tower.
Range: 400
Cool Down: 185 seconds
Champions it can benefit:
Hardcore Pushers/Split Pushers

Summoner Smoke Bomb
Reduces the vision range of all champions and minions around you by 50% for 3 seconds and causes your champion to enter stealth for 2 seconds.
Range: 850
Cool Down: 190 seconds
Champions it can benefit:
Weak Early Gankers/Suicide Lanes

This way, it provides much more choice. For example, is that enemy Jungle Lee Sin going to pick Flash and gain even more mobility or pick Recruit and gain more pushing presence? Is Jax going for the ultimate safe lane with Fortify and Golden Age or is he going to get Smoke Bomb and Flash for the increased sneakiness and mobility? Is Nasus going to choose Teleport or Destruction for either more stacks or extreme late game pushing, or is he going to pick both and leaving behind Flash? Is Trundle going to go to war with the enemy towers with a Destruction and Recruit combo? THE CHOICE IS YOURS!