Options include:
Individual parts - If the condition inspection has shown that the cylinder block and most of the engine components can be reused, then the most economical option may be to purchase individual parts. The crankshaft block and piston/connecting rod assemblies should be carefully inspected. Even if the block has minor wear, the cylinder surfaces should be honed.
Set with crankshaft - Kit (if available) consists of a ground crankshaft with new matching repair main and connecting rod bearing liners.
Sometimes such a kit includes reconditioned connecting rods and new pistons with rings (such a kit is called an "engine kit"). If the block is in good condition, but the crankshaft journals are worn or scored, then the most economical option may be a kit with a crankshaft and other individual parts.
Small set with block - The small kit consists of an engine block with crankshaft and piston/connecting rod assembly mounted to it. New bearings are installed and all clearances are set correctly. The existing camshaft, valve components, cylinder heads and add-on assemblies can be installed to the block with little or no shop machining required.
Complete set with block - "Complete" or "large" kit includes small kit and oil pump, oil pan, cylinder head, cylinder head cover, camshaft, valve components, timing gear and chain (or belt) timing drive mechanism. All components have new bearings, seals and gaskets. All that remains is to attach the intake manifold, exhaust manifold and attachments.
Consider carefully which option is best for you and consult with local machine shops, parts dealers and experienced engine rebuilders before purchasing or ordering new parts.