Personally, I'd opt for the VPN, as it can be more useful for other situations, like Bob said.
Also, I'd rather have a slow and secure connection than a fast and unsecure one. Seedboxes seem a little overkill due to price... maybe in the future if I get more disposable income, but for now, I think a VPN would be a wise decision, even for more than just torrenting anime. Or anything in general.