I hear what you're saying about 3 cross and radial.
I really like the look of this 3 cross crow's foot in here. Although I think it works especially well because of the large hub flange, keeping three spokes parrallel to each other.http://www.terminalvelocity.demon.co.uk/WheelBuild/
Radial is fine, just don't do it on hubs that look like it shouldn't be dont.. e.g. Hope skinny hubs
Shimano and Suntours are perfectly strong enough. It is not of course as nice a wheel as a 3x.
BUT where is the fun in just building 3x, that doesn't seem to be the point there.
Have fun, try the crows foot then at least you can say you tried it.
Spoke lenght calculation should be easy.
CRC will split their 36 spokes into different lengths, though looks like you may have noticed that already.
Why not go mad and do the cross in silver and the radial in black,