Fuse upgrade from factory.....

I currently have a Theta Dreadnaught 1 5x200 amplifier which uses a Buss MDA 15amp 250V fuse. My 
Preprocessor is a Primare SP32HD with a T2amp AL 250V. I want to upgrade the fuses to maybe an S.R blue/black,  Furutech, Audio Horizons, Brimar Audio. 

 I have also read to raise the fuse rating by .25 - .50amps. 

Can anyone direct me with the better choice for my two pieces......Thanks in advance.......