Hi Live Life! Welcome to AA!
Being that 135L is roughly 35 or so US gallons you could go with way. I'm a freshwater person (born, bred, water fed Oorah!) so I always lean toward the freshie side of things but its whatever you would think that you would enjoy the most. Look into what's accessible in your area, for example my local fish store is mainly freshwater so its easier to go there for my supplies. Its not up to us to decide for you what you should do because at the end of the day its only you that has to be happy with the end result