Radio/speaker ? panel truck

I got a radio at a swap that I want to use in my 40 Ford panel truck. It is a fm/am 12 volt neg ground made by Automatic Radio model AUF 2565 A. I think it's out of a 60's era car. My question is what should I look for in a speaker or speakers that this older radio will power. I know nothing about audio stuff. Here is a picture of my panel you don't see many.
Pete
Flathead .060 over,max 1, t-5, 9 inch, 4 inch drop,

 

ive been wondering the same thing. ive got some experience with newer audio systems. but it seems the older radios only used 1 wire for the speaker. is this how yours is, too?

 

the reason they only have one speaker wire is their was only one speaker in the car. and it only needed a power to speaker and grounded to the ch***is ground. Why would you want to use the old radio when they make new high tech that looks like the old ones? Just wandering

 

Well I look the look of this old radio and I checked the cost of the high tech ones that look old style and the cost kills me. I only need the radio when I am on long runs which is only occasionally.
Thanks Pete