create payment module for wordpress plugin

Project Description:
Hi,

I've got a wordpress plugin called Image Store (https://xparkmedia.com/plugins/image-store).

I need a payment module writing to allow the collection of debit or credit card details to be processed offline. I need the first 8 card digits to be emailed once the order is processed and I need the rest of the card details to be stored within a database.

The script will need to remove the stored details from the database once the payment has been processed.

I already use a payment module for a totally different site which does exactly what I need but its for WP-ECommerce...
http://www.visser.com.au/plugins/offline-credit-card-processing/?platform=wp-e-commerce

The API for the image-store plugin is https://xparkmedia.com/image-store/docs

£30 maximum budget.