DIY - conceptual question

If you were considering a single channel, basic tone stack version of a fender bassman, has anyone determined what the minimum chassis / enclosure size would be? On exsiting Fender amps, the chassis / enclosure (at least the width dimension) is defined by the two channels, and 7 or more knobs. Do away with most of that, and the transformers, tubes, circuitry would become the defining factor of the width dimension. (although Sunn 200s is basically the single channel, minimal tone stack amp, and its every bit as large, but thats another issue) I'm thinking that a single channel, 3 or 4 knob amp with a pair of large transformers, the usual tubes, etc. should easily fit into a standard 19" rack sized chassis / enclosure. Can anyone point me toward some documentation either confirming or suggesting an alternate size? Has anyone ever read anything that describes how close together preamp tubes, power tubes, transformers, misc cirtuitry, etc. can be placed before you begin to cause problems from interference, heat, or other issues?