If by DIY a PCB you mean produce the board yourself, I will give you a one word recommendation. Don't.
In my experience the quality of all the Chinese PCBs I had made has been excellent, only time I've had a problem is when I sent them a bad design. And the price is unbelievably low. Think about it, 100mm x 100mm for $2 US, Just under $4 total price in your hand if you choose the lowest-cost shipping option. And that price is for either a 2 layer or a 4 layer board, with holes drilled, slots routed, plated through holes, and solder mask. You'll probably have a hard time getting just the blank PCB material for that price, then you have to deal with cutting it, drilling it, and worst of all etching it yourself. It is only a good thing to do if you are a true masochist.
For the soldering station, I don't think I would spend that much money on a clone. I would personally choose either something cheaper like the Hakko, which is very well known to be a decent quality piece, or perhaps spend a bit more and get a nice used JCB, Metcal, etc.
Oh sorry forgot context yet again.
I meant to DIY a soldering station. But I already have so many…
Bismuth is OK for prototyping. Yes the bond will be weaker and more brittle but your parts won't fall off the board on their own sitting on a bench.
The problem is that if you use such solder, you will contaminate your components and your soldering iron tip, etc. with it. And that will introduce it even where you don't intend to be just prototyping anymore. All it takes for joints to become brittle are trace amounts of bismuth.
And yes, parts will fall off the board by themselves with this solder after a while in extreme cases - the joints do crack. However, far more often you will get broken joints and flaky connections which are a huge pain in the ... to debug and repair constantly.
There is no reason to use such solder for regular soldering. This is a special solder that is used only for assembling very sensitive specialist components, such as some RF ones or in special alloys for desoldering. All other components can withstand regular lead-free reflow temperatures without issues.