ok i'm not familure with all the LS1 stuff yet but I do know my way around a Gen 1 Block and I KNOW that a Cam that gives you 100+ HP is going to be a racing cam and you will not have any vacume. ok maybe a little but not enough for street use. for street I would suggest a mild to hot cam nothing really big but bigger than stock obviously. the only thing with LS1 cams is that they are alot more expensive than a Gen 1 block Cam, Mine will cost around 150-200 yours will be like 300-500 give or take. I would suggest getting the Comp Extreme Energy Cam or the SLP Cam.
here is a Head and Cam Package I would look at if I were you.
http://www.fbodymotorsports.com/inc/...l?v=1&pid=1291
it has the cam and the heads only problem is you have to assemble them, (Not that big a deal) and for a little added horse power I would grab me some Aluminum Roller Rockers from Summit for the LS1. you'll be making SWEET horsepower then.