First time posting so I hope I've got this right.

Could I have a little advise on seat choice and having searched for the seat concerned can't find it occuring, but apologies if it has been answered elsewhere.

I'm travelling on the 777-300 LHR - PHX (and back) in WT.

Historically I've always waited till check in to choose my seat and travelling that route when it was the 747 I didn't really have a problem with the seat I'd have chosen but am aware that BA may not offer me an aisle. I'm now thinking about booking a seat and not being familiar with the layout other than the reviews here I wanted to ask for some views.
I'm someone who would rather be disturbed than disturb when it comes to visiting the 'facilities'. On my flight row 28 at the front is unavailable as usual. 29C and 29H have also been booked. Does 29B allow me to get out of my seat without disturbing the person in 29C given there is no 28C. I also like the idea that I might be able to sneak a little more legroom putting one leg in the right side of 28B (obviously with 29Cs permission as I don't want to be an inconsiderate traveller). The alternative to 29B would be row 37 (not fussed which of those as I wouldn't disturb anyone getting up)

Coming back I would also have the options of 29C and H as they haven't been booked yet.

Views / advice welcome and thank you in advance.