TrollDragon
Headphoneus Supremus
I run the exact same setup in my Mk IV, the 6HM5's are a great bang for your buck.I have the 6HM5 running with the 6H30Pi. In my opinion, this combo sounds a tad better than the 6N6P-ir which I also have, but again, YMMV depending on what kind of cans you have.
The 6H30Pi are stock tubes that came with my LD Mk4 (not SE)!
The 6HM5 is warm and airy which I like much. It probably is the best value for your money before you move onto the more pricy C3g.