You can do a full volume mash either using a large infusion mash tun ('no sparge brewing'), in some heat controlled tun or in the brew kettle directly by putting the grain in a mesh bag (=BIAB) that is removed before you boil. While you do no sparge, it means that some sugars remain in the grain and you will be slightly less economic (low efficiency). You can compensate by using more grain and you can even dilute with some brewing water to adjust wort gravity. The beer is going to be perfect. Letting the temperature settle at 170F is optional if you immediately proceed to boiling step. The idea in this 'mash out' is mainly to inactivate enzymes and thus stabilize the result of the mash (sometimes also lower the viscosity of the mash for sparging), but in real world things won't change too much if you proceed straight to the boil.
If you prefer to sparge, doing a batch sparge is the easiest way and won't be that much different compared to no sparge. By sparging you will reach higher efficiency (more wort from the same amount of grain) and a smaller mash tun will be enough.