I am not sure I fully understand here.

part pay by avios is when you buy a cash fare and reduce the cash needed by paying some avios. You do that by making a normal cash booking on ba.com and the avios reductions will be offered during the process. This isn’t an upgrade process - you should pick whatever cabin you want to start with. You will earn based on the cabin you book.

avios and money is when you book a reward flight but choose to reduce the avios needed by paying more cash. You do this by making a normal reward booking and the avios & money price points are offered on the quote page. As with normal reward bookings you don’t earn any TPs or avios. You need to book whatever cabin you want to start with, this isn’t an upgrade process either.

upgrade with avios is when you book a normal cash fare and then use avios to upgrade in to the next cabin if there is reward availability. You earn based on the cabin you paid cash for, not the upgraded cabin.