How to use Membership with this plugin

My goal is to collect additional information when people register for a membership level, such as phone number, business name, facebook page URL, second contact name, second contact email, etc.

The following plugin "Simplr User Registration Form" allows admin to build different/separate registration forms with different custom fields and role. I only need the custom field feature. The role of a paid membership is always subscriber.

Video:
http://vimeo.com/23532472

Free version
http://wordpress.org/extend/plugins/simplr-registration-form/

Paid version
http://www.mikevanwinkle.com/simplr-registration-form-plus/

Custom fields:
http://c4775374.r74.cf2.rackcdn.com/wp-content/uploads/2011/04/Screen-shot-2012-01-27-at-3.12.11-PM.png

The paid version even has the font end profile page:
http://c4775374.r74.cf2.rackcdn.com/wp-content/uploads/2011/04/Screen-shot-2011-11-23-at-10.18.19-AM.png

My question is: How to use this plugin with the membership plugin? So people can provide additional profile (custom fileds) information during the membership signup process.