Create a WordPress Template for auto emailing members (of a larger group) that fall within a geo-location range

I am looking for a responsive Wordpress template that generates an email to members (of a larger group) that fall within a range of a given geo-location. A website user should log-on to my website. The user provides a location (geocode, or location name, or via pointer on Google maps, ie. Manilla), and a search range (ie.100 meter, 250 meter, 500 meter, 1km, 5km, 10km, 25km). Based on these two inputs, the template should search in my "members-database" which members fall within the range, and generate and send an email to these members. Potentially I will add a third input on which the members will be selected. The email contains text as well as the two (or potentially three) input values. In addition there will be few additional input fields generated by the user which will be added to the email (ie. a date and a number). These few additional input fields will however not determine the member search scope. Also the user name should be added to the email. Next, the user should receive an email where the members are listed that received an email. I want to limit the number of members that receive an email to 10, 15, or 20. At random or choosen by me/ the admin. Language should be in English. Translations may follow in a next version, so that should be taken into account when building the template. Thanks, Jan-Willem