as guest speaker or as a guest speaker

[Roadster]

I cannot make up my mind which of the following versions would be more appropriate:

We would like to invite you as guest speaker on the occasion of our annual general meeting.
We would like to invite you as a guest speaker on the occasion of our annual general meeting.:?:

 

[billmcd]

I cannot make up my mind which of the following versions would be more appropriate:

We would like to invite you as guest speaker on the occasion of our annual general meeting.
We would like to invite you as a guest speaker on the occasion of our annual general meeting.:?:

Either one is OK, of course, but for some reason that I can't really explain, I prefer the one without "a". It just seems to suggest more importance to the invitation.

 

[bhaisahab]

I cannot make up my mind which of the following versions would be more appropriate:

We would like to invite you as guest speaker on the occasion of our annual general meeting.
We would like to invite you as a guest speaker on the occasion of our annual general meeting.:?:

Both are possible. The first one suggests that there will be only one guest speaker and the second that there will be more than one.

 

[Roadster]

Thank you, that sounds logical!