I love these- https://www.marksandspencer.com/us/adaptive-cotton-bodysuit-3-16-yrs/p/P60283230.html?dwvar_P60283230_color=XB&pid=P60283230&quantity=1
Size 15-16 fits me well (5.7, 143). Currently out of stock, but they restock frequently. They also have other staff for "big babies", just search...