On your checkout page the Country select list should always post whatever the value attribute has for the selected option. So regardless of what option is selected the corresponding value for that option should be posted to the action of the form. This is not something that would change based on the comparison value that you are using.
I think that you might just be setting the dynamic selection incorrectly. The part of the code that you have listed as being at the bottom is a dynamically populated select list for the country. This is not what you want to be doing. Instead you should just be setting the 'select value equal to' to the value from your recordset. Select the checkout form on the page, then in the property inspector click on the dynamic button. For the 'options from recordset' leave it set to none, then for the 'select value equal to' use the lightning bolt icon to set it to the recordset value that holds the country code.