and it does have 45amps on the 12v rail so thats good.
Eh, not really. That's only 540W for a supposedly
750W unit (and a TON of amps on the 3.3V and 5V rails to make up the difference...). Not very encouraging, and Ultra PSU's aren't exactly known for their quality.
Regardless, yes, it'll fit in any normal ATX case.