If I were to purchase a 27" iMac with 32GB. How will the come configured? 4 8's or 2 16's? Does anyone have a firm answer on this?

Never ever buy a 27” iMac with more than 8 gb of RAM, Apple charges a fortune for RAM. Buy 32 gb from either Crucial.com or Mac sales.com. Installing RAM in it takes less than 5 minutes and you will save hundreds of $$. Upgrading RAM will not affect the warranty.

I just bought 2 27” 2020 iMacs, installed 32gb of macsales.com RAM for $135 each computer and now both have 40 gb of RAM.

Nobody knows! You don't have confidence to replace RAM by yourself? Then you will pay $600 extra to Apple install 32gbs of RAM, and pay somebody else to install another 32. I install 32 gbs RAM, from OWC, with Apple 8 gbs RAM, now I have 40 gbs, myself, in my brand new 2020 27" iMac. It is not hard. But it's your call.

Please watch https://eshop.macsales.com/installvideos/imac-27-inch-5k-late-2015-memory/iMac20-1/, if you don’t think you can do this then perhaps you should not own a computer. Seriously it is extremely simple, requires no tools and any one with 1 able hand can do. :-)

Okay. You will laugh once you have completed it.

The warranty is not affected by you installing RAM, that has been Apple's stance for over 15 years. There is no patience to consider, it so simple if you do it you laugh at yourself for being concerned at all. If you have enough coordination to take 1 step without tripping you can do this. Seriously, if you want to waste money by having someone else, including Apple install the RAM well that's your decision.