I've decided to build a 18 watt in head form. It'll be a two channel job but instead of a tremelo I'm going to put in a TMB channel, and have it such that one channel is is less gainy and the other will be more gainy than standard. I'm thinking along the lines of the 'Plexi' or 'TMB' model of Trinity amps (I'm not going to use their kit though). This is what they say about it:
The Plexi is voiced to sound period correct for a Marshall Plexi Lead. Screaming guitar lead tones at a much lower volume. The amp can thump and grind with less compressed tone than the other 18 watt variants. The Second Channel (Normal Channel) provides way more overdrive than most 18 watt normal channels while the Plexi channel is capable of the best clean sound we have ever heard come out of an 18 watter. With a pair of greenbacks, you'll be shocked how period correct it sounds. Crank up the gain and you are in crunch tone heaven. The clean boost just adds another dimension, it nails all those old AC-DC tones dead on and has way more gain on tap if needed.
The TMB amp is a high gain amp that does the 80s sound very nicely. It is intended for musicians who want plenty of grind. It does ZZTop very nicely. It is both responsive and aggressive. The second channel is the Normal channel from
the original 18 watt design. This amp does classic rock crunch to metal.
So that way I'll get an old-school channel and a higher gain channel and lose the tremolo. I'm going to pair it with a 2x12 closed back cab with Warehouse Reapers (G12H30 clones). Well, thats the idea anyway. I'm most likely going to order the kit from Valvepower in the UK, they make little kits for a single channel amp in a steel cage for little money, but I'm going for the traditional look, standard size head. I know a guy in JHB that has built two of these amps already and he says they're very good quality.