You can find the Intel Edison Platform in different versions:
Intel Edison Compute Module
Intel Edison Compute Module + Breakout Board
Intel Edison Compute Module + Arduino Expansion Board
Mouser has different models, the ones you mentioned above are related with the Intel Edison Compute Module, you can see in all the options you posted the same specifications and prices.
There are not an Edison 1 and Edison 2. There is only one Edison, Mouser has these models in order to have different and more certificates to sale the products to different countries.
If you want to buy the units from Mouser I suggest you to contact them for more information about the models the y offer and which is the best option for you.
You can also send an email using this form Intel Support to check if there is another option for purchase a high volume of units.
So just to clarify there is not a version of the Intel Edison that only has the u.FL connector as a test point?
There seems to be a lot of buzz online that some editions can use the u.FL with an external connector and others don't use it and are just a test point.
If I just attach an antenna to the u.FL connector on any Edison then I will be using that antenna as my Wifi Antenna?
Yes, there is one. You can purchase a version with an u.FL connector working as a test point or for an external antenna.
Take a look at the Hardware Guide for the Compute Module (Section 3.7)
Note: The internal antenna versions also have a u.FL connector on the board, but it is only used as
a manufacturing test point. Do not connect an external antenna to a board with an internal antenna
Can you unsolder the ceramic antenna or a resistor near it if you use an external antenna?
For me it works just fine with an external antenna. But if I unsolder the ceramic antenna, I can use the space below it for components.