Joys of WordPress Multisite. FeedWordPress plugin is great for aggregrating but can cause server preformance issues with Multisite. On large installs better to avoid RSS and use a plugin that uses post indexer plugin.
If you allow embed code you could use the FeedWind RSS widget ( http://feed.mikle.com ). This widget provides a range of options including ability to display post excerpt and you could try setting a wider width to embed in a page.