Dual Gun Pressure washer set up ( question )

Hey I need some technical help

I want to buy a dual gun machine that will shoot 4000 psi 8 gpm does anyone have any idea who sells these?

I want to pressure wash the joints between pavers on residential driveways I have been using a BE 4000 psi 4pgm Belt drive for a year now ( at it works great ) but want to speed things up with a dual gun machine so I can get 2 employees working on the same machine at the same time. ( 4000 psi 4 gpm each)

the closest I could find was 3000 psi 8 pm… https://www.pressurewashersonline.ca/collections/gas-washer-cold-water/products/be-honda-truck-mount-dual-gun-gas-power-washer-3000psi

I realize im gonna have to hook up to a tote tank and get 1 inch fittings filters etc… does anyone have a similar setup?

is it better to have 2 belt drive machines vs 1 bigger one?

im based in Montreal Quebec Canada but have ability to get stuff shipped to NJ

Thanks!