Adding subscriptions to "Store" plugin

Hello,

 

I would like to add 3 subscription [options] to the "Store plugin" for merchants/vendors wanting to advertise their product/services to my website. Each subscription option MUST have a "limited" number of products capability. My question is, how much customization will be required to do this??? I did notice that subscription was available, but I wanted to use it for the Store plugin and not for my existing members profile webpage... Also, I would like to offer a 30 day free trail offer [in all 3 subscription options], without using PayPal adaptive. After the 30 day free trial offer expires, merchants/vendors can start their monthly subscription.

 

I would greatly appreciate any responses...