Are there some fruits that have a high enough fiber content, so that the fruit sugar carbs don't get quickly digested (trying to avoid a sugar high)?

Glycemic index: Berries, cherries, apples and pears are all "low glycemic index" forms of fruit. They are also nutrient dense and must still be balanced out with heart healthy protein foods such as nuts. Combining a starch with a higher protein food can slow the uptake of simple sugars and reduce the glycemic load. If you are a diabetic be very careful with portion size. Even low glycemic foods can inc glucose.