I had added 110 to two C Dory 22's. None of these had huge power draws--all were less than 15 amps. Thus I put the shore power inlet plug on the starboard side, under the gunnel, where it is protected. I put a breaker and on/off switch under the galley counter aft on the aft bulkhead. I then put one outlet just outboard and back of the helm seat for the galley (GFI), and one under the rear seat of the dinette. The 3rd outlet box was next to the breaker/fuse under the galley counter, where I put the plug in for the battery charger. Simple, and all of the components are well protected and out of the way.
The 25's and larger have refrigerators, microwaves, water heaters, air conditioning, etc, and they require the 30 amp setup. Rare to find anything near that in a 22.