graeme_p - if I understood correctly, all you want is "improve your useful information site's position in the SERPS". You don't look specifically for a seo monkey to do link requests or build a social profile. You are targeting "better ranking in the serps". Correct?
How many "content pages" does your site currently have?
Small sites often hunt for outside links before they've built - to it's capacity - their own sitewide link profile.
If your site has i.e. 2,000 useful content pages, you can gain tremendously by posting on your own blog short posts with useful related news and information (not automatic feeds), and including links to your existing content pages.