A300 sucks, and I have to use it all the time!! Although row 31 is the first row of Y, the seats appear slightly narrower due to the tray table stowing between seats. I usually get 32 B. For a rapid exit though, I prefer 31B or 31D.

A340 is very nice (alas,I have only flown in F on the -600), but I can't comment on Y, Y+, or C. Row 44 is the forward-most row in Y and looks ok. There might be some bothersome foot traffic to the toilets and leg-stretching, and mini-conferencing in your 'near space'. Again, I migrate away from thos factotrs if at all possible. My personal picks would be 45/46 B or D.

TG's Y seat pitch has always been pretty good on large aircraft. Depends how important the 32 hours of sitting more comfortably are against whatever the savings might be for TG Y vs SQ Y+. Up to you!