Could anybody recomend an excellent strong staple gun please.
The Arrow company makes a number of models that will work well on a variety of tasks. Check out their Website.
Even if you don't buy Arrow, make VERY sure that whatever staple gun you do buy takes the Arrow size staples. I made the mistake many years ago of buying a Swingline. The staples are non-standard, and True Value hardware the only place that carried....a few sizes. Arrow staples are stocked in every store I know of.
As far as the gun itself, when someone (thankfully!) finally walked off with my Swingline, I bought one of the "push" rather than "squeeze" type of staple guns. Much easier on the hand, much better results.