Sounds like Murat might have the answer you are looking for (perhaps he could ship direct to your destination in Greece?). If not, I noticed this week that Apnea.co.uk in the Channel Islands now sell Riffe spearguns and they are currently on sale.
100cm Riffe
90cm Riffe
The Rob Allen railguns are available with single 16mm (Sparid), single 20mm rubber (Caranx) or double 16mm rubber (Tuna). I suspect a 90 or 100cm Sparid would be powerful enough - but a single 20 or double 16mm would certainly pack a mighty punch (you can always change the rubber configuration later). The built-in rail on the extruded aluminium barrels adds rigidity - double bands is a common configuration. To me 90/100cm sounds huge for shooting into caves -- I would think 45-75cm would be more appropriate for that (perhaps with a multi-prong tip) -- but I've noticed it is relative (i.e. people in clear water, used to long guns also prefer longer guns on their reefs - perhaps to keep their options open and/or due to big fish). RA also offer some highly rated reels. Not sure what the second hand price of a railgun would be -- never seen one for sale (I've looked).
Railguns
Reel & accessories
Some of the Greek & Italian (& Guernsey of course) wooden guns are impressive though, almost works of art in some cases.
