I would look into school supply websites/ catalogs. Many schools have periodic auctions of such items as well.

Several

Live with two seams , 256.50 each

Get three 4' x 12'

Contact for custom. another source

https://fujimats.com/pages/contact-us-1

Have ONE SEAM

https://www.enhancemats.com/products/gym-floor-covering-court-armor-rolls/

WHICH MEANS........

A seam isn't the end of the world. : ) is beyond common even in gyms, and beats tiles.

I like the tiles since dropping weights can often do damage then you just rplace a tile I buy about a dozen extras for clients .

We used rubberized flooring like Jan posted and cut to fit.

I went with one seam and ordered two 6x12 mats. Thanks for the help.