Where can I buy the BNC male to RP-TNC female at a reasonable price?

I have a linksys wrt54gl and i want to attenuate the signal using rf attenuators.

I need:
reverse polarity TNC(male) to bnc/sma (female)
bnc/sma(male) to reverse polarity TNC(female)

The rf attenuator would be connected in between the 2 adapters. Is it supposed to be RP bnc/sma to RP TNC or is what i have right?

I found a fairly cheap RP-TNC-Male BNC female adapter on ebay but can't seem to find a BNC Male to RP-TNC Female anywhere.

Does anyone know of any sites that sell the BNC male to RP-TNC female at a reasonable price?

(I am also ok with SMA if anyone has any good links)

http://www.rselectronics.com/
http://www.digikey.com/
http://www.farnell.com/

Thanks for the links but I couldn't find a RP-TNC-FEMale to BNC MALE adapter.

If anyone else knows where i can buy the adapter let me know.

Thank you.