Check out a BAT VK-300xSE or a Jeff Rowland Concentra II. I haven't heard the Moon I-5, but I have heard the integrateds from Krell, Classe and Levinson and the Rowland and BAT beat them all. I would go with the BAT myself, although the Rowland isn't far behind. It comes in 3 options, solid state, 6922 tubes, and the SE version with the 6H30 'super tubes'. Good luck.
John
John