^^ great advise above, but I will tell you what I tell most people who come to me and ask this same question..... In reality no matter how you do it, it's not a matter of if it breaks, it's a matter of when. If this is your only car and if it broke it would leave you in a very bad situation, and if you don't have the money or ability to replace things such as head gasket, or pistons, then it might not be a very good idea to do anything. You can put something together and it may never have an issue but most of the time something does eventually happen and it will take time and money to fix it. If you're okay with that then I say go for it, try to use quality parts, buying used is not always bad, and defiantly get a good tuner to tune it. Good luck.
JSH