Based on Sixty-Fiver's Headset Modification v2 thread here, I went with a Nitto Periscopa quill stem using a Tange G32STR Aheadset, the 26tpi nuts from the original headset, and a Sinz seatpost clamp. Works like a charm. I think the Raleigh fork is more than robust enough to accommodate a quill stem.
On the BB, I went with Phil Wood cups and a Shimano UN72. If I had it to do over again, I might cut the BB shell down to 68 and rethread. That way, you open up the whole world of contemporaneous BBs and cranks.