At 82k and with only (only???) a 7.5 I think 133 might be beyond optimum width for early planing.You might find the 122 planes just as early (if not earlier?) than 133 if you do limit yourself to the 7.5.(its my biggest sail size aswell)
I know someone will disagree with this comment but I`m pretty sure that there is an optimum width for a given sail size/weight.If you go above it (width) you are just gaining extra drag.
The 122 is still a wide board and will carry 7.5 easy.I`d guess around 12 knots minimum.
The 122 will definitely give you the widest wind range.(over 133 )
To be honest I think I`d go 111 at your weight ! You might lose a knot on bottom end but you will enjoy the 15 knot+ days much more.
Its hard to call on pumping;if you pump like me you will lowethreshold of each board by a knot or 2.If you are good at pumping (and fit!) you might knock as much as 5 knots off.