Replace my 2nd molar (extracted) with an implant or pull my wisdom tooth with braces ?

This movement is usually very difficult and almost impossible. If the wisdom teeth were not fully grown, chances would be better. I would remove the wisdom tooth and do implant in front of it. 

Nigel'This really depends on the position of the wisdom tooth and how far the space to be closed is and if it is upper or lower.  There are several factors that make this movement possible or not possible.  The sinus position on the upper jaw might also have an impact on implant placement.  If the 2nd molar is already gone and the wisdom tooth has already moved into the space partially, this could allow orthodontic success.  Ask you Orthodontist to look at your particulat situation.Good Luck!