Okay, not really cuztomizing but I figure that this would be the best place to get an answer.

I have a crate palomino v32 2x12 its thirty watts and I drown out the other members of my band if I go past 2. (I got it mainly to teach the drummer a lesson ) I love the sound but I want to know if I can just use one of the speakers and how to go about doing this while keeping both the left and right channels...and not blowing the speaker. I've heard having a single speaker gives a tighter sound and is easier to distort, but seeing as the only model at the store was the 2x12 I didnt have a chance to compare.
i've seen some fancy rear panel switches that let you go from mono to stereo. You could buy/make one of these and switch it to stereo when you only want to use 1 speaker and just not connect anything to the other input.
Gibson Explorer
Jackson Soloist SL3
Orange Tiny Terror
Mesa 2x12
Does your amp run on 4 EL34s? You could pull the outside 2 power tubes and make the amp run on 15 watts. Changing to one speaker won't really do much difference in volume. The 15 watts will overdrive easier and will sound nicer since you are pushing the tubes harder.