We use Xero for our accounting and plan to integrate it with Zoho very soon but I need to know how to best optimise the data on Zoho.

We're a contract cleaning company and some of the contracts we have involve us supplying our customers with cleaning materials. These cleaning materials are either invoiced for separately or included within the monthly invoice for cleaning (as an additional line item).

We have a number of different suppliers who supply us with cleaning materials. We have price lists from these suppliers - we buy from our suppliers (by creating a purchase order) who then deliver directly to our customers (who we then invoice). Obviously there's a purchase price (a price we pay to the supplier) and a sell price (the price we invoice our customer for). 

How can this workflow best be reflected within Zoho CRM? Bearing in mind we want to link this eventually to Xero? At the moment we create POs within Xero and then manually invoice our customers - but through our integrations we want these POs to be indexed against our suppliers within Zoho (whilst referenced to the customer we're ordering for). Conversely we want the invoices that are generated - if they are invoiced separately - to be indexed against the Account. 

Some of the mandatory information within Zoho is just confusing - I've created a few supplier records for our key suppliers and associated a number of products that they supply us; the information I've put within it is relevant to us (for example with a minimum order price / minimum order quantity but we also have pack quantity price with a pack quantity number).

When I look at the PO module within Zoho, and try to create a PO for our supplier, it then prompts me to select products, but the prices have to be derived from a 'price book' with a designated 'list price'. I'm a bit at a loss as to how this all fits in with our workflow are highlighted above.