just buy a stroker crank, new pistons and rods that all work together. depends if you use a 5.7 or a 6.0 rod as to what piston to use. machine work should always be an included factor. youll need new bearings rings etc. you can clean the block and deck it by yourself theres alotof things you can do on your own. the block needs to be clearanced so pick up a set of nice dremel bits and go to town for awhile. when i trimmed those on my 383 i smoothed the oil valley and stuff too. if you use the stock powdered rods you may have to clear the stud and block, otherwise aftermarket rods will allow them to clear just fine.
i assume your going to cam it as well? clean the bores for the lifters well, check all your valvetrain componenets. i dont usually reuse lifters as they are cheap. now would be the time for some port and polish work but make sure your using good casting heads. springs and all that would be wise as well.
it all may seem very costly but i built mine all for 2000 just about. that included machine work, most materials that i didnt havem bearings gaskets, and all that. i kept my costs minimal, made a few friends along the way that gave me suggestions advice and recommendations and had a solid engine. unfortunately for you your tune will cost a biut more, because i certainly wouldnt skip that on a vortec. you could not do it and it may run fine, but you could squeeze quite a bit more power out of the engine with a tune.