UR Colossus Ramp (Standard)

This is a modified version of a deck I saw on a daily MTG article. Its main function is to ramp up into metalwork colossus and combustible gearhulk. Saheeli adds some extra power late game by making copies of our giant robots (triggering the gearhulks ability whenever it is copied).

I am a bit unsure of the two drop creature that I want in this deck... On one hand I want a creature that is able to crew the large amount of vehicles in this deck, but on the other hand I would like a creature that allows me to ramp up to the colossus even faster. Hedron crawler let's us get the colossus out on a potential turn 4, while a lupine predator extends that to turn 5 but can pilot any vehicle. Eldrazi mimic is another interesting choice as it can copy our colossus when it comes into play, allowing us to attack with it almost immediately.

The sideboard is another thing that I am not so sure about... I included some spells specifically to deal with smugglers copter if it is an issue. Harnessed lightening, incendiary sabotage, and ceremonious rejection accomplish that goal. I also included fleetwheel cruiser as a more aggressive option for a vehicle instead of the barge in a match up that might require it. I may need some more pilots, dropping a vehicle or two.

If you have any suggestions to improve the deck let me know!