To these ears, the best sounding entry level tube integrated is hands down, the Vista Audio i34. There isn't much that affordable thing doesn't do well, and best of all, the tubes are cheap and the unit is self-biasing. It's probably the only sub 2k piece that I've ran that wasn't quickly put in its place by my 6k+ integrated amps.
That said, the Prima Luna suggestion is also very solid. Though I feel their sound quality falls well below the aforementioned Vista Audio piece, they nonetheless offer solid and reliable performance. The tubes are easy to replace and that self biasing circuit makes for very worry-free ownership. The best thing Prima Luna has going for it is a wide distribution network, which makes it easy to audition one before forking over the green.
Between these two options, I think you'll be happy. Both will match your EPOS monitors just fine.
