local amendments may apply. in one town in this area they require a mininum 2" rigid on a service. I think they got tired of people having bent risers.
Here in Tulsa I generally like to use 1 1/4" emt. I know , I know, you shouldn't use emt outdoors but we do it all the time and it seems to last a reasonable amount of time in this locale.
Did he give you the Amperage you got to carry? or the wire size? is it single or three phase?