I see that you can use preview images now when someone

I see that you can use preview images now when someone signs up for a site but it pulls from the theme that you made your templates with.

I am using one theme for mobile sites but want to display different niches for them to select from so a way to upload your own images say like a mobile site in a phone for chiropractors ect.. .or maybe different layouts for them to select from would be great.

I am also using whmcs provisioning and noticed if someone buys a site there, then the preview that you normally see on the sp-signup.php page does not show.

https://www.814media.com/billing/cart.php?a=add&pid=9

Would there be a way to use your own uploaded images to show for your templates as previews and also have this carry over to the WHMCS Provisioning page so people can select their look before they pay?

Thanks Scott