well a skimmer is always great to have and IMO a must. (It is easy to be temped to add more livestock later on also)
I think you will get varying opinions on the canister filter and UV. I would say the canister is fine if you clean it a LOT... I don't believe the UV does any harm, but whether is helps with ick has been under debate in older threads.....
hope this helps and feel free to ask further questions