It doesn't look stable to me,the DIY bulkhead kit doesn't has big flange to hold it in place is very easy to break off if something hit it,I just rather pay $10 for a regular one at LFS,at least I known they last for long time.
For the purpose of a trash can water storage, I would try but not for the actual tank. Like Ith03 said, rather spend $ and get something proven and safe. Hell, you already spent 100's if not 1000's on everything else.
