I am sorry guys, but the only advice I can give you is search on Ebay or else and wait for a good deal. Personally, I am not familiar with modern production, but there are sites where you can ask that, cos they are not selling them only, but have lots of experience to, especially for PrimaLuna amps, here, probably one of the best you can find, just send them an mail and point out your preferences http://www.upscaleaudio.com/index.php/products/tubes.html
In the mean time, safe some dollars and be patient.
In the mean time, safe some dollars and be patient.