Most are on the dropship model these days.

These days (in the US anyway) most manufacturers will be used to this model and it'll be a whole lot less of a headache for you.

I'd recommend setting up a website with some example products (from shutterstock for example) to show the manufacturers that you're the real deal before calling or emailing.

If you have a great website that you can point to, the manufacturers will feel more confident approving you because they can see how their products will be presented. Make sure to mention your marketing strategy too and give them a locked in launch date.

Call around the top 50 and you should get approved from enough to get started. Call back in 30 days and point to the sales you've got in that time. You'll get another bunch onboard.

Margin is typically pretty good in furniture as it's a high perceived value - You might make initial calculations around 35% (varies wildly obviously).