How Will I Know Which Power Supply To Buy?

Solution
1st, do you move the acer MB into the new case? or just buy that acer MB.
If you will buy that acer MB, make sure the MB will come the "back panel shield". Also if you will move the MB into the new case, also make sure the Back Panel Shield can be removed.

You will need a 400W PSU for your system, because the PSU will depend on the GPU+CPU, they will draw most of power from the PSU. So if you are in USA, this one Corsair CX-M 450W for $30 is more than enough. https://www.newegg.com/Product/Product.aspx?Item=N82E16817139146 otherwise read the linker for How to choose a PSU. http://www.tomshardware.com/t/power-supplies/
1st, do you move the acer MB into the new case? or just buy that acer MB.
If you will buy that acer MB, make sure the MB will come the "back panel shield". Also if you will move the MB into the new case, also make sure the Back Panel Shield can be removed.

You will need a 400W PSU for your system, because the PSU will depend on the GPU+CPU, they will draw most of power from the PSU. So if you are in USA, this one Corsair CX-M 450W for $30 is more than enough. https://www.newegg.com/Product/Product.aspx?Item=N82E16817139146 otherwise read the linker for How to choose a PSU. http://www.tomshardware.com/t/power-supplies/
 
Solution