Buying from TonyMac guide?

I hackintoshed my PC for fun just to see if I could, and while 99% of things work and it's fine enough for me, I had a question about the buying guide here

My sister is a MacOS user and will not switch. This was fine when she bought her 2008 and 2011 Macbook pros for $1000/$1100, but now the cheapest Macbook Pro in Canada is $2000 after tax and the specs are laughably bad (Core 2 duo, seriously?)

Needless to say, she's not going to be upgrading.

However, her Macbook pro is getting too old for her needs, so I was wondering; How do I go about getting a flawless hackintosh? Can I mix and match the parts on the buying guide? I see there's "CustoMacs" which I am assuming is just a place for people to start, but what about swapping the hardware up? Are all the parts on that guide compatible?

Basically what are my best options at a hackintosh that works as flawless as possible?

Thanks!