V2 and V3 heat beds are functionally the same, the only difference is the connector to the AP board. The AP board is also different, and the AP board cover shape will tell you which version you have now.
You really do not have a choice. Bambu made the transition to V3 very early in production and no longer offers the V2 as a replacement. My V3 X1C was delivered in January 2023, anything newer should also be V3.
If you do currently have a V2, the V3 will come with a new AP board (once). Follow the link in the part description to coordinate the change - you need a Bambu support ticket to be sure you receive the new board for free.
The replacement takes a fair amount of time, but the wiki is a very good guide. There are lots of screws of different sizes and lengths. I printed up pictures of the screw locations, glued them to thin cardboard, and poked holes to hold each screw as I removed them. This organizer made it much easier to prevent loss and to be sure each screw went back exactly where it came from. I kept the cardboard and it has been handy a couple of times for other work.