You need a MTB crank, not a road/gravel one like the Tiagra, the Tiagra will be designed for a 68mm BB, External BB MTB's have a 73mm shell as standard

No mention of the rest of your spec, but any 9/10 speed from say Acera, Alivio Deore or SLX would work, you would need to check the ratios, and probably budget for a new BB as well if you want to move away from FSA.

FSA and Shimano external BB's are a very similar spec, but depending on your crank/BB combo may not be similar enough.