Actually, that's what boosting the image cache in the reader will get ya.

But yes, the Claws solution is probably better because of the item-removal issue -- the reader doesn't have any control for storing items (vs. merely caching them) so an item may only stick around for one or two refreshes before the app dumps them. Which is why I refresh manually.

I don't need to hold onto 60+ news items per feed when on the go, so the builtin reader has been fine for me, but YMMV.