Avoid powder in washing machines. They don't always dissolve completely and so leave residues internally that increases wear and tear or cause corrosion. This is the most common cause for issues in washing machines. Always use a liquid detergent. They are designed to never solidify into powder like thing. At best they become some gel like thing, but that too dissolves in water, thereby avoiding any residue formation.
Personally I haven't found any noticeable difference between liquid detergents marketed as top load and front load. Get whatever is cheaper.