I don't know of a specific kit with cam, heads, intake and blower. If you give a few details about what you are trying to do I'm sure we can steer you in the correct direction. I wouldn't buy a GM crate engine with the intent to pput a blower on it unless it was a real mild combination. You need to set your ring gaps properly for running a blower. I have no idea what the GM crate engines use as far as ring end gap. That is not an area to guess. There are a lot of mail order/crate engine dealers out there that can set up your short block for you. That way you will know it is built for use with a blower. If you buy a generic GM crate engine, you will have to tear it down anyway to prep it for blower use. Your crank will have to come out, to have either a double keyway or extened keyway cut (I personally prefer extended over double). You will aslo want a short water pump, keep the compression around 8:1. Since you are new to blowers I would suggest picking up the book called "Street Supercharging" by SA Designs, it is an excellent book that will really help you get up to speed.
Don't get me wrong I am not trying to discourage you, you will love the blower. Just make sure you do it right so you can enjoy it without problems. You can buy a complete blown engine from Speed-O-Motive, it will be custom built and you can have it tailored to your needs, when it's all said and done, it won't cost you anymore than buying a GM crate engine, prep'ing it right, buying a set of heads, cam, and blower kit. Don't forget carbs, linkage, scoop and air cleaners.