I have a 3320 and use a MX6 John Deere chopper mower. It pulls it fine but the tractor is actually rated for a 5 foot which would probably be a better choice in case you get in some heavy mowing. I happened to have a bigger tractor I can use with the 6 footer if I get in the big stuff.
On the CX loader, you have to buy the heavy duty bucket as an option. It is definitly worth the few extra dollars. The heavy duty bucket has extra reinforcement on the top plate, sides, and bottom.
The spikes on the bucket would be your choice and would depend on what you use it for. I do not have teeth and use only the heavy duty bucket as is. It does everything I need it to do. It can pick up ay type of rock or dirt including digging into sod or regular field soil. If you were getting into compacted clay or something similar you may want a tooth bucket.