>>3409654>>3409664Another vote for Godox, V860IIS or V350S depending on size or power requirements (since it will be your first flash you probably don't already have a collection of rechargeable AA batteries).
The attached pic is a size comparison between a V860IIS and a TT350S (same thing as the V350S but without the Li-ion battery) on Sony bodies.
You might also want a X1T-S or XProS transmitter to try off-camera flash.