Good NOS tube dealers/New prod. tube alternatives?

In a previous thread, I asked about good lower priced replacement alternatives to the Siemens tubes (6DJ8, 6922, 7308) in my SF Line 2 SE preamp. Thanks, I received a lot of good feedback. But now I have a few more questions:

1. What tube dealers have you had good experiences with? (If I am going to pay big $$$ for NOS Siemens/Amperex tubes I want to be assured that the tubes I receive are as advertised.)

2. Are the only new production tubes manufactured from Russia, China and Yugoslavia?

3. Has anyone used tubes from RAM labs? or Ei tubes? Are the Siemens Falcon logo tubes genuine Siemens tubes?

4. Are cryogenically treated tubes better?

Thanks again,
Fernando

Current system consist of:

Genesis 350 SE speakers
2 - BEL 1001 Mk4 amps
Sonic Frontiers Line 2 SE
Cambridge Audio D500SE cd player
Perp Tech. P-1A/P-3A (Monolitic Power ps)
Audio Magic Stealth Power Purifier (6 outlet)
AR Turntable