To make a permanent system from the Logic Noise potpourri, there's a ton of choices that need to be made. Here's a record of what I've been thinking.

• Chips: Clearly, we'll need at least one of each chip that's been featured in the Logic Noise series so far. That is to say: 40106, 4051, 4040, 4015, 4017, 4070, and a 4069UB.
• Hard-wired and convenient vs Flexible: This is the crux of the biscuit: what separates a Moog Modular from a Minimoog. So far we've been doing everything on a breadboard, which is the extreme of flexibility, but suffers for convenience. I'd like to be making simple sounds with three or four patch cords, and sequenced things with five or six. Not patch-cable spaghetti, but flexible.
• Special Functions: Flexibility is great, but re-wiring up the cymbal or bass drum circuit every time would be silly. Some things will just have to be hard-wired modules. We use a few 40106 oscillators every time -- they should just work out of the box.
• Connectors: Ideally, we'd all be rich, have huge workspaces, and the every input/output would have a well-labelled banana jack. With eight chips and 10-12 pins per chip, assuming 1in^2 and $0.50 per jack, that's something like 200 in^2 and $100 just in connectors for the whole system. That won't do. The compromise is to break everything out on male pin-headers and use female-female "Dupont" wires as patch cables. It's cheap, small, and easily compatible with breadboards.
• Multiples: Many connections to the chips will need to be doubled or tripled. Example: you'll want a tempo oscillator that can feed multiple clocks. I'll put two or three outputs where necessary and make up the rest with a few well-placed multiples.
• Power: Easy. 9V battery. Small, cheap, convenient. Works with rechargeables if necessary.
• Overall flow: Oscillators -> clocks / switches -> special modules -> output mixer. Not that it needs to be hardwired, but that keeping the order in mind will help layout.
• Audio Out: Ideally, headphone and line out jack. In practice, it's easy to do the line out correctly, but headphones really want a dedicated driver/amplifier and their specs are all over the map. So we'll fudge and do something with the 4069UB chip that'll probably work for both. Wish I had space for a speaker, but anything plausible will have crappy bass response anyway.
• Fine points: Inputs/outputs in the same order as on the chips, or grouped into logical sets, or grouped and ordered. Since space for writing legends is going to be tight, I think re-organizing stuff to make as much intrinsic sense is the only way to go.
• Luxuries: It's nice to have some LEDs around to help debug. A few tie points to VCC and GND never hurt. Pulldown resistors on all the sensitive inputs?
• Art / labels: It'd be nice to describe all the chips on the board artwork. OTOH, we're going to be cramped for space. Sexy artwork for the back side is a must.