For safety I would go with an X of 12H30 and V30. You could also match 12T75 and 12M25, which is common practise. Against the principle of same dB, I have also heard people using 12M25 and V30 and being very happy.
With a 100W rating it remains a risk of blowing the Greenbacks if you go to max on your 5150 (6 in a small room? Goodness!)
Another thing: Don't expect the speakers to solve it all. They will make a difference, but the cab itself, wood, construction, size, etc, will make a huge difference too. Don't think your Peavey cab with 4x12 Celestion will sound the same as e.g. a Bogner straight 4x12 with the same speakers.
Less relevant for close up recording but still very audible in real.