I’m struggling to get my head around how to set up my post purchase flow. I’m getting very confused! 

I have different products which require different post purchase emails regarding the turnaround time, how to care for the product etc. These include:
Mud kitchens - approx 3 week turnaround time 
Fitted Tablecloths - approx 7 days turnaround as I have to sew these
Swim Bags, swim caps and goggles - if in stock, sent 1-2 days after purchase 
Wet weather gear including overpants, craft aprons, fleece lined pants, shoe covers - if in stock, sent 1-2 days after purchase 
Magic Potions - if in stock, sent 1-2 days after purchase 
Reusable water balloons - if in stock, sent 1-2 days after purchase 

I also then want to have separate emails for new customers and return customers.

I want to send emails pre-shipping and the post-shipping. 

And what if they purchase a fitted tablecloth and a swim bag for example. 

How can I set this up as a flow (in the simplest form) but so that each customer receives the correct email with information relevant to their purchase? 

Thanks
Alana 
www.mudmates.co.nz