As you say wheels are usually the first option considered.
Probably the simplest option is to look at an industrial wheel/castor supplier. For example this site has a huge range of wheels castors and other parts for moving and handling.
Wheels are typiacly rated with a maximum load, note that if you use 4 castors it is usual to make sure that they are rated so that 3 are adequately rated for the total load ie if the load is 1000kg you need castors rated to at least 333kg.
Castors are generlaly pretty good for reasonably smooth surfaces like a decent concrete floor. Soft or uneven surfaces may require pneumatic wheels which tend to have significantly larger diameters.
Castors have the advantages of being self contained, vesatile and compact and they can often be fixed directly to th estructure you want to move but only work well on reasonably smooth, hard surfaces.
Typically harder wheels give less rolling resistance on smooth surfaces but are more affected by uneven floors.
Inertia is a fundamental property of matter and there is nothing you can do to decrease it. But when moving things by hand the ability to control heavy loads on wheels becomes a problem before they are too massive to get moving.