That should be a 747. Best UC cabin in the fleet - just 14 seats in the nose - feels very private.
The seats are all the same size and, yes, some do find them claustrophobic due to the high dividers between each one. Note that due to the curvature of the aircraft, the further back you go the further apart they are across the aisle (so 6A & 6K are almost touching - great for couples -whereas 12A & 12K are acres apart).
If I were you I'd try for 6A, 6K, 7A & 7K as they'll keep the four of you within easy chatting distance of each other. Failing that try for four in a row eg 7A, 8A, 9A & 10A. Rows 11 & 12 are close to the bar which some find annoying although 12A & 12K benefit from only having one next door neighbour.
To be honest, though, there's no bad seat in that cabin and I think you'll be happy wherever you sit.