The problem with supplements is that they can interact with medications. For instance, omega-3 oils can interfere with "blood thinners" like coumadin/warfarin or aspirin and result in hemorrhaging.
Unless his blood shows a lack of one of the B vitamins, just one multivitamin per day is sufficient. It is best to try just using healthy foods for 2-3 months and see if that will improve his cholesterol numbers rather than piling on a bunch of supplements. Remember that any supplement that has any effect on the body is a drug - just an unregulated, uncontrolled one.
For high cholesterol, he needs to follow a diet low in saturated fat (only lean red meat 2-3 times per week). Most of his protein should come from lean chicken, fish, and legumes (beans, etc.). Any vegetable or fruit is acceptable within reason. While he won't want to eat a whole pineapple because of the sugar content, a slice or two (fresh or canned in pineapple juice) is not going to harm any diet. I am appending some 1,800 calorie diabetic diets which are healthy for everyone to follow. They are low in simple sugars, and heart healthy so they are good for the cholesterol as well. They will give you an idea of what types of food he can eat and about how much. You can tailor the calories depending on his current weight and if he needs to slim down or add calories. If he needs to add calories, he can just have more lean protein and green vegetables. In general it is better to serve whole grains rather than white (processed) ones, whole wheat (or other whole grain) rather than white bread. Solid shortening, butter, margarine should be avoided. There are some stanol-based spreads that actually reduce cholesterol (Benecol, Smart Balance). Olive oil and flaxseed oil are his friends as far as cholesterol are concerned, but they have just as many calories as all other oils and shortening/butter, if weight is a concern.