301 need advice

I just bought a domain from the auction, its pr 5, 9yrs age, dmoz registered with solid backlinks. im planning to 301 redirect it to my new site. my question is which site would i build backlinks to, my new site? or the site that i just redirected(purchased)? im getting mixed answers on this one, thats why I need your advice bhw. cause im eager to start my new campaign.

Thanks!

Bump. anyone?