HP DL380p G8 - upgrade to 25SFF drives

Hello, 

I have HP DL380p G8 server in my home lab. I would like to extend my 8 SFF server about 25SFF drive bay. I would like to ask you

1. do I have to use the second controller?
2. my server have two 460 W PSU. Is it enough for 25 hard drives?

thank you