First of all 4 stroke gasoline engine choices are not all that plentiful. 2 stroke gasoline engines have generally ruled the roost for many years because of the simplicity and available power to weight. That being said the four strokes have been making some very good inroads especially in the smaller displacements.
Most if not all four strokes you will find still have to use a gas/oil mix similar to a two stroke. In fact 16:1 or 20:1 which will distribute more oil deposits than a standard 2 stroke at 40 to as high as 100:1.
Any gasoline engine needs a fine and delicate hand adjusting carb settings. With gasoline the air fuel mixture has to be right on to work well at all throttle settings where nitro fueled engines have a much courser needle valve adjustment. Nitro has a much wider range air fuel wise that the engine will operate in.
Size of your chosen model will depict how many options you have for engine choice.
Not trying to talk you out of a gasoline four stroke by any means. Perhaps instead you might tell us your choice of model and size then some with experience might be able to suggest an appropriate power plant. Are there reasons why you are leaning towards a gasoline four stroke? There is lots of experience on the forum and lots of advice and help if you want or need it.
Dennis