LT1 impala to a 383 stroker help!?

I just bought a black 95 impala ss lt1 with 26,591 miles for $15,000 and i love it to! But my question is what exactly do i need including 'everything' to do this job. i want 400rwhp and i dont car about the price. i just want to keep my original block. the only reason im asking this is because i dont know sh*t about engines. i've been to jegs and summit racing.com and looked at their kits but im sure theres more parts i need so could a expericed person tell me everything i need to do this job for 400rwhp. again i dont care how much it cost, i want the best parts and to keep my original block! thank you all!