It wouldnt matter. You would be asking this the other way round of you bought the 6.
Tarmacs are great bikes. I have 4 of them.
I have a 16 with disk and sram axs 12 speed. Its heaver too 18 ish lbs.
but it is rock solid.
ebay. Carbon wheels from king bike. It's a woman but I cant recall her name. As far as getting wheels that will fit they can make anything you need. These are dt swiss hubs 60mm carbons with xdr freehub for axs12 speed for 500.00. Hard to beat