SET amp comparable to First Watt SIT 1?


I’m currently planning to change my speakers to high efficiency horn from modern high end speakers (B&W). The speakers would be Volti horn speakers.

For amp, A friend of mine has First Watt SIT-1, which sounds great to my ears, but I have always been interested in tube SET, especially 300B. The problem is there are too many choices around, and I have read several online reviewers stated that 300B amps don’t sound as good as First Watt SIT 1, except extremely expensive ones with NOS WE300B.

Any suggestions?

My budget is around 7-15K. I don’t mind second hand ones, but I wish I could compare it with my friend’s SIT 1 before I decide to take it or not, so second hand unit is probably not an option.
tmare
Is an SET design really necessary? I have a VAC amp that uses 2 300b's per channel, and it drives just about anything. I had it on a pair of ESL's for over 2 years and had absolutely no problems. 
You can also get a Wyetech Labs SET Sapphire 300B monoblocks with plenty of power to drive your speakers [ 18 watts RMS ] It's also on sale now at $7800 a pair

Thank you so much for the precious comments again.

Regarding the rooms size, my rooms size is 15ft x 30ft, ceiling is 8-10 ft (room is a bit irregular), and listening position is about 10-12 ft (3m) from the speakers. I mostly listen to jazz, classical (piano, chamber) and vocal. I usually do not listen to orchestral or rock, but I’m afraid that my current normal listening level would probably be a bit louder than the other SET people, considering the level that the SET exhibitors play at the audio show. It is definitely louder than Audio Note demos, but not loud as those loud solid state demo rooms. I start wondering if 300B SET is really powerful enough for my propose, since several people mentioned it... I also wonder if 100dB or 105dB speakers make a big difference.
Hi tmare,
You have a generous size listening room. You’re beginning to express some concerns. Why don’t you call Volti and talk with the builder himself? Parallel SET 300b, 845 or 211 SETs are options. Ask the builder his thoughts regarding OTL amplifiers as well. Discussion with him is a good starting point in my opinion.  Man oh man,  you have wonderful options. 
Charles
Hi Charles, thank you for another great advice. I really wanted to try 300B SET, so I know I should just go for it, at least for my first SET amp.

The reason why I have not contacted any manufactures on the list is I feel my candidates should be narrowed, and I don’t want to bother those people with my ignorant questions, also I don’t want to be biased by them. I’m planning to contact all manufactures when my candidates are finalized. and I’ll do it very soon. I have learned a lot from this thread already, and I’m much more confident what I was trying to do!