You don't say why you want to raise the boom, but, reading between the lines, I assume you just want more clearance for people and perhaps a bimini. The easiest way to raise a boom is to have your sailmaker install a cringle for a flattening reef about a foot above the sail's clew. Ease the mainsheet, and use your reefing gear to pull the outboard end of the boom up to that cringle. It doesn't sound like much, but it's surprising how much extra clearance it provides, and it doesn't sound like you need much clearance. It might be just enough for your purposes. Canting the outboard end of the boom up by a foot isn't very noticeable, visually, but if you try to increase the clearance by raising it 1.5 ft., it'll start to look odd.
Adding a flattening reef is not expensive, and using it like that doesn't cost you a terrible amount of sail area, and it doesn't ruin your sail shape. Obviously, the boat will perform better with it's factory configuration, but a flattening reef will accomplish your purpose, and, for general cruising, the boat's performance will be satisfactory. If you want to race or if you need all your sail area in light air, you can just shake out the little reef, and your sails will be back to factory configuration.
If you make any more "permanent" alterations in your sails or rigging, such as cutting down your sails, you'll undoubtedly hurt the value and marketability of your boat.