It follows module frame thickness. AIKO Neostar 3S+54 and LONGi LR7-54HVBB are 30 mm. That is the Cobalt 30 mm end clamp, black with black frames, mill finish with aluminium frames.

On flat roofs those are two systems. Landscape uses the landscape base and 1792 mm ballast tray. Portrait uses the 1800 mm base. Do not mix the plates.

No. Rail, clamp, hook, ballast tray and side plate are sold loose. Count from the layout in the Cobalt manual.