so I have been looking for new 8 lug rims for my 93 f250 with a hub bore of 87.1mm and I have been struggling to find any that I dont have to use hub centric rings but if I have to use hub centric rings what should I get?

 

If you are sure you have 87.1mm now then just buy any 8-lug rims exact or larger than 87.1mm and add the hub centric ring, you have far more selection when doing so, ID goes to your hub, OD goes to your rim.
If you get a wheel with smaller than 87.1mm then you get adapter, a reducer, and not the ring anymore.
I had a nissan that takes 66.1mm and I was looking for a full size spare wheel + tire. I found a cheap wheel off a ford mustang on craigslist with 70.5mm (if I remember) but I couldn't found any with 70.5mm or I had to wait from a seller in China but I didn't wait, I bought a 70.6mm on Amazon and it worked still, just need to use a hammer. So I bought 70.6mm (OD) to 66.1mm (ID) hub centric ring and how much is the ring, not much. That said, don't even think if you need to spend more buying the rings separately. With the lack of selection you might end up spending far more.
What size of ring to buy all depends on your new rims that you are buying. If you don't already have a digital caliper, just buy one, dirt cheap $8 on Amazon or $2 on AliExpress, you can check Temu too.
Finding the correct or best offset is far more difficult, and adding spacers cost much more than hub rings, keep that in mind.