Link online payment to the site

The site is either a self-written, or a Yii framework (why or because sisadmin claims the latter, but there are doubts).
We need to tie the savings bank, there is uncertainty with the checks. Sberbank offered to buy and pay monthly for ATOL online cash register. VTB in turn offers to install a "soft" that will use physical cash registers (which is easier) would like the performer who faced online checks