Odd shape
Doesn't look like any modern psu will fit
The psu overhangs the hard drive mounting bay
Also the power connectors are incompatible.
There's a
mod that can be done but doesn't look like a straightforward procedure. He also moved the board to another chassis. Unless you're handy modding psu's which isn't recommended, there's not a lot you can do. The power connectors are totally proprietary.
Time you've paid an electronics guy to wire one up for you and invalidated the warranty on new psu, if anything goes wrong, all money down the drain+increased risk to fry system.
You could've bought a different socket 1155 board. You'll also need a new chassis & associate your windows license with a microsoft account in case of any problems with activating windows. Since it's probably an oem version it will invalidate if try to transfer to another board. There isn't often any upgrade path with proprietary pc's more often than not.
You're basic proprietary nightmare.