I feel your pain! Since you're now looking for a condenser you might want to seriously consider buying a Parallel Flow condenser. They are 30% more efficient than the older fin & tube style. The only problem I found going that route was the Parallel Flow condensers never seem to be taller than they are wide and they have to be mounted with the tubes parallel to to the ground.
I ended up buying a 22" x 22" Parallel Flow condenser for about $135. You can see my installation on the radiator at the following link Parallel flow condenser installation.
It just so happens that the original radiator is 21" wide and the condenser just fits edge to edge with about 1/2" hanging over on each side to mount to. If you looked at my pictures in the above link you'll see how I did it. If you do decide to go with the same condenser I can give you more detailed mounting instructions.
I opted to go with the Parallel Flow because they are more efficient and work well with R12 or R134a. I'm switching over to R134a mainly due to R12 being harder and more expensive to get.
Here is the Parallel Flow condenser that I bought.
I'm also adding two 10" electric fans in from to help keep things running cool
I'll be posting pictures of the fan installation sometime in the next few weeks.