I see you haven't had any responses here, so I'll try a couple of suggestions. First, try doing a search on EL84 in the tube section of Audioasylum (www.audioasylum.com). Second, when I researched this the common wisdom was that the nos Phillips were the best. For current production I would suggest JJ. There are several dealers, but I have had really good luck with Eurotubes (www.eurotubes.com) They can provide you with a very tightly matched octet at a very reasonable price. Hope this helps.