Unless there's a specific reason that you need a UV
sterilizer... I wouldn't bother. They don't give enough benefit in my mind to justify the cost of buying one. Good water parameters will do more for a tank than a UV
sterilizer ever could.
That being said, UV
sterilizers are rated for different things. Some are rated for killing algae (more specifically used against green water). Others that are slightly more powerful are for bacteria. Finally, the most powerful ones are for parasites. So in order to make a suggestion we need to know what you're hoping to fight against.