Whatever you end up buying will need monthly maint.. Yes, I've worked on shredders also. Go to a store which sells sewing machines and pick up a bottle of sewing machine oil. Depending on how often you use your shredder, you should saturate a couple of sheets of paper with the oil and run them thru the blades. Believe it or not, keeping the wheels (blades) clean and lubricated will help to keep them sharp.
And if you get a paper jam on one side or the other, take the unit apart, clear out the jam (best you can), re-assemble and re-lubricate.
Your shredder will last longer and you will be a happy camper!