For the shape of the tent, it would be a better fit. If it comes at great cost, could buy a 3x3 tent, if that is cheaper.
They have very similar umol/s PAR outputs, so the primary difference is the shape.
SE4500
12-hour operation - 90% is probably a good starting point
18h - 60%
If the specs are accurate, this might be a better starting point than 67% / 100%. It's slightly overpowered for 8sq ft.