Accounting, Invoicing, Tax invoicing GST invoicing waybills etc

I’m looking for experienced accounting help with ongoing assistance. The main focus will be on invoicing but I’ll require assistance with tax invoicing, waybills and other related tasks. I don’t currently use any specific software, but am open to suggestions. Ideally you'd be able to provide advice and guidance on the best and most efficient software for my business. I'm open to a long term partnership if I'm satisfied with the results.