This is my way to play ziggs on mid, have a lot of fun but not so easy to play.
In this build we can see that we don't need to be in hurry, it grants more mana for beginning and will give a boost of damage for mid game to finish with a nice build.

The runes are focused on ability power and magic penetration, as you could see most of the runes are scaling AP for grant boost of magic damage on mid game.
Quintessence grants instant AP because you need a certain bonus at the beginning.
As usual the marks are magic penetration

Masteries are usual like a normal mid, grants you AP and some utilities for mana and the duration of buffs

Spell sequence are the basic, you must max the Bouncing Bomb (Q), next Explosive Minefield (E), and then Satchel Charge (W), i choose to pick (W) at level 4 because ganks aren't immediate so you can focus on (Q) and make more damage to enemy champion and steal a recall at beginning

I think ignite and flash are the best choice, you can cover a big are with the combo Satchel + Flash and then using ignite to finish the enemy.
However even ghost or exhaust could make up for your movement speed