I would recommend a Dawes Kingpin. I just purchased a Dawes Kingpin non folding and replaced the wheels withh modern alloy rims. I did this with a Raleigh but had to widen the forks to get the new rims to fit. I also like the build of the Dawes better than the Raleigh. Here is some more on the subject of both,
http://raleightwenty.webs.com/thedaweskingpin.htm

http://www.flickriver.com/search/Dawes+Kingpin/

http://raleightwenty.webs.com/