Go ahead and use the Pyramid bottom bracket. Grease the bearings well and the threads lightly. Make sure the threads on the bottom bracket shell of the bike are nice and clean.
Read all the sheldonbrown.com stuff. Like Scratcher said, don't worry over the chainline too much. Follow Sheldon's instructions on how to measure and get a rear wheel hub that'll fit or be very close.
I'd imagine if that Pyramid bb gets you anywhere between 105mm to 112mm, whatever fixed wheel/hub you get will work. May have to use a spacer on the inside of the rear wheel hub or have the wheel redished.
Have fun.