Don't know how to do a poll but, here are some themes I am thinking about and some corresponding ideas. If you have additional ideas or other themes, please reply, thanks!
A) Dinosaurs: excavation kiddy pool, dino tail favors (
here)

Superheros: cape favors, mask photo props (hubby works with LEGO/Marvel so we could get a lot of gear)
C) Race cars: rent a food truck for food, DIY car photo booth, matchbox favors
D) Firetrucks: we live near a fire station so we could get a firetruck to stop by our house, firehats, dalmation favors
E) Little man: mustache theme
Re: Poll: best boy's 1 yr b-day theme
~*~*~You're Such A Pretty Melody, I'm Just Another Tattooed Tragedy~*~*~
DS2 was born May 8th and I already decided his first birthday party will be Cinco de Mayo theme. Close enough, plus margaritas. But nope to renting a food truck.
OP do whatever is easiest and save the fun themes for when he is old enough to enjoy them.