Yeah i actually just fixed it by changing it to what you had on my own.

Basically: if ( zen_not_null($referrals['sources_name']) ) {

had to be changed to: if ( zen_not_null($referrals->fields['sources_name']) ) {

I did have one more question though - on the customer account creation for the referals dropdown it appears to be pulling Please choose your country for the default selection of the dropdown list, underwhich my input referral sources are located. Any thoughts on how to change this?

Thanks again and ranger lp you're awesome :)