wide lens for an fx30

so i currently have a 16-55 g f2.8 which i love but i really want something wider.

im torn between a sony 16mm f2.8 plus the fisheye adapter or the sony g 10-20mm f4

the 16mm + adapter is 300$ cad

the 10-20mm is 600$ cad (brand new on fb marketplace)

i shoot run and gun and want a light/small lens for a gimbal so the 10-20 seems like the best option but f4 scares me a little for low light settings. also want to get a zoom lens in the near future (probably the g 18-105 f4) so the 16mm will make that happen faster, please help me decide!