If you really, REALLY want a dedicated PSK-31 XCVR kit, then I think
your only option is this: (And it's expensive.....210 EUROS + Shipping)http://www.qrp-shop.biz/DigiFun-PSK-Transceiver
(I don't think even NJQRP is offering "The Warbler" any more.....)CAVEAT EMPTOR:
I bought the above mentioned "Digifun" kit when it first came
out about 10+ years ago. It was missing many, many parts. I had
to wait a YEAR for an English version of the assembly manual. (At
the time of purchase I was told it would be ready "in 2-3 months").
And then the manual (and rig assembly) was a nightmare.
(Not to mention hand winding IF transformers with #40 wire.
Yes....#40 wire......diameter = 0.00314")
This is the only kit I have purchased in the last 20 years that
I could never get to work.......and I have built a LOT of kits,
ham radio and others!
To be fair, maybe they got the kinks worked out...but I kinda doubt it.
I have never read about or heard of anyone successfully using
or building this kit rig......
GL ES 73, Ken AD6KA
PS: Your best bet (and good luck with it) is to post ads
looking for unbuilt SWL PSK kits. Hey, you might get lucky! :>