Event Instalment plans

I would like to see events booking offering instalment plans. Where users can confirm their place and pay for the event in two halfs.

Basically a duplicate of the register (individual) instead called register instalment plan (individual).

Which uses the exact same form as register individual just when clicking through to confirm it takes you to PayPal where you set up a subscription with half the payment upfront and the other half automatically being taken a month later by PayPal.

Formsmarts manage to do this with their forms.

And in the back end where registrants re listed if they paid through this method they receive a orange icon or something, to show they've paid half but its not a complete (green tick) untill the second half of the payment is received.

I would really really like this as I'm having to create a link to a formsmarts form which offers the instalment functionality as you don't at the moment