[Amps] need air variable capacitors

[w2cqm at juno.com]

I need several air variable capacitors with a value of about 250pFd.
Spacing can be moderate since they will be used on the antenna tune side
of a VHF project.  Prefer the long type single section  rather than a 
multi-sectioned broadcast variable.  Approximate dimension is 2x2x8". A
regular plate tune HF air variable  would work  with 1/8-3/16" spacing. 
Thanks, Ron W2CQM New York City