[Request] Keeping the site running smooth and efficient

I manage a news site that is currently importing several dozen posts a day into various categories through RSS.

I have been unable to find a plugin that will run daily to automatically delete any posts that match a given criteria (it, Any posts in Categories 6, 8 and 12 older than 30 days and any posts in Category 5 older than 7 days).

I'm having to manually go into the site each week and do this.

Any chance of getting one that does this and optionally optimizes the database using Cron?