Ordering stock – Do I order more lines, or more stock of fewer lines?

Hi all,

I'm starting a new ecommerce business. I will be holding stock of soft furnishings – throws, cushions etc. My big question is on my first order, what volume of stock should I be ordering? I'm not doing Amazon FBA just yet.

Starting with Shopify, connected to eBay, Etsy and various other marketplaces.

My question is – what volume of stock should I order, and how many lines? It is a difficult question, as my supplier has a lot of nice products. It is the difference between going shallow on volume, but big on range, vs. the other way around. Each has their own merits.

If I go shallow on range/lines, but good volume for each, then:
(A) My site will look a bit spartan, with only a few products.
(B) If they work well, I won't run out of stock quickly.
(C) If they don't work well, I am stuck with a quantity of slow moving stock.

You see my conundrum? How have you approached it in the past?