Minicraft's DC-8s (1/144) are very nice, as is the Minicraft Cessna 172 (1/48). Welsh Models of the UK (http://www.welshmodels.co.uk/) make some very nice 1/144 airliners, mostly vac-forms, although some of their later releases include resin wings and stabilizers.
Check out Airline Hobby Supply (http://www.airline-hobby.com/). He carries just about everything that is available, and his service is very good.
And if you're really into airliner models, I highly recommend joining the Airliner Modelling Digest, a Yahoo! group. Lots of knowledgeable and friendly people there (http://groups.yahoo.com/group/airlinermodelling)
Michael McMurtrey
IPMS-USA #1746
Carrollton, TX