Valvetrain and cam installation questions

Ok this is a very complicated question (for me) and I really appreciate anyone who takes the time to read this. I am a newbie with engines. But mine has 194,xxx miles on it and i know it isnt going to last much longer. I want to buy a new 331 short block from d.s.s. Say i buy preassembled twisted wedge heads. How would i go about choosing, buying, installing a cam, lifters, rods, rocker arms etc? Heads are assembled so springs should be installed already but probably not rockers. I know i'd need flycut pistons for valve clearance and i believe they come standard on d.s.s. shortblocks. Now in the future i want to run some boost too. Should i get the low compression pistons and should i get a blower cam now, or get one later? How hard is it to install a cam when the engine is in the car or at all for that matter. Do i have to degree the cam? Sorry for the "20 questions" but you guys are the only people i can turn to in order to learn this stuff. I want my hard-earned money to be spent well. I myself believe it would be much cheaper to buy a shortblock and heads, cam etc seperately and install them myself than to buy a longblock already assembled. Please help me out! Stangnet is my only hope

thanks for some info. d.s.s does give you a cam and heads (even the afr 185's i wanna run) with valvetrain and everything except accessories and intake basically. but its VERY expensive. 331 with afr 185's is about 5000 and if i sit and add it up seperately its almost 1000 cheaper. i dunno but i think i could save alot assembling the stuff myself.

just the 331 stroker with block (crank rods pistons and i think a timing chain is about 2500) thats the shortblock i am talkng about, long block has heads cam too.