URL forwarding/seo

We have recently bought a load of domain names (our product names) with the intention of forwarding them all to our main site. We’d like to do it all as search engine friendly as possible, ultimately we’d like these new urls to make it to the top of search results (which shouldn’t be too hard as there’s very little competition).

At the moment they forward to our main site’s url using http redirecting. Apparantly. I wondered if changing the DNS to link it to the main site would be more search engine friendly but i have read neither option is better or worse… is this true?

Also, I wonder how search engines will ever come across these new domains if all they do is link one-way elsewhere? I imagine the new urls could lend weight to the importance of our main site and vice versa…if so, how would we go about maximising this and getting them recognised at all?

Thanks in advance!