Well, there isn't a huge difference between the two types, in my experience. A decent lf pilot is going to be out maneuvering a hf pilot of similar skill, but it's a question of degrees. Either pilot is going to be out maneuvering everything else in the game. The big question is if you are capable of the precision and patience needed to take a lf up agaisnt heavies, very heavies, and bombers. A lf can do it in the right pilots hands, but it's not going to be quickly decided. I'd suggest going with a heavy instead, it's a little more forgiving to the newer pilot.
As for what and what loadout, that depends on what you are going after, really. The Falcon and Kingfisher are probably the most popular choices but my personal favorite is the Moldy Crow. It's a bit big for a hf, but it handles well enough and can pump out a bumload of hurt. It really fits the vigilante type, too.
As for loadout, well, you'll likely find the hfs a bit underpowered if you have only flown larger ships. I suggest, for the crow, four shield busters (three primaries and the turret), two hull busters, a missile (shieldbuster is my choice but either works for our purpose), a cruise disrupter, counter measures, and a hullbusting mine.
You are generally not going to want to joust, since almost everything you face is going to be tougher than you. So e-kill and strafe plinking away at the enemy shields while dropping a mix of cruise disrupters and missiles. The goal of dropping a mix of both missile and cruise disrupter is to make them run out of counter measures before you run out of either type of missile, though it's more important to have a reserve of cds in the end. Once you have his shields down and he's not botting em back, start dropping the mines on him. Occaisionaly letting him get you into a joust, or a semi-joust so he runs nose first into it is an acceptable way to go about it. These tactics aren't fast, but they should get you the results you want.
It's likely others can give you better combat advice, and this is much easier said than done, so you probably want to wait and hear what others say.