Tyan Thunder n4250QE S4985-E Motherboard with Tyan B4985V50V4H-4P-E Chassis

I've got a great deal of problems finding a proper PSU for this motherboard and actually fits in this chassis.

As the redundant PSUs are dead, I don't care about redundancy, just to get a simple PSU to work with this board. The most important part is getting a working PSU and it would just be a plus if the PSU would fit in the chassis.

The motherboard is Tyan Thunder n4250QE S4985-E.

Please provide any pointers.

Tyan Thunder n4250QE S4985-E Motherboard with Tyan B4985V50V4H-4P-E Chassis