I thought one of the Raleigh fans would have been along by now.
Seatpost, easiest way is to measure the inside of the seat tube with a pair of vernier calipers, it is also worth having a look in the archive (see the title at the very top of the page), as it may be mentioned in one of the Raleigh catalogues.
The BB axle will depend on the cranks, so if you already have them and can tell us what model they are, then chances are someone will be able to help.