I want to set up a second account on Ebay linked to the same email address and Paypal account. Or even just the same Paypal account would be fine. Is that possible?
yes i do.

I have 2 ebay accounts and my buyers pay with paypal at the same email adress on paypal.'

you can also register more than one email address to the same paypal account if ebay. i have 3 emails under one paypal acount and i can be paid via any of those emal addresses to the same paypal account, so i see no reason why it wont work.
You can have the same paypal account, but when you create a new eBay account you have to use a different email addr.
http://www.youtube.com/watch?v=wx7IahpPuxs

that might help