Netsuite does have it's own add on called AP Automation. Recently watched the demo and it looked alright. Were quoted $299/month. There is currently a component for bill pay through HSBC bank which we don't need but it sounds like in 6 months or so they will offer the AP automation side of it only. We are booking some demos with other companies (Tipalti, Stampli, Mineral Tree) but haven't done so yet so not sure how they compare price/feature wise.