James, I would suggest the Naltrexone. I don't know if you're in the UK or not, but NHS only provides Selincro for drinking reduction and Naltrexone for continuing abstinence after supervised detox (from my understanding). This may vary by the area you're in and Joanna at C3 Europe might well have more details for you. If you'd rather use Selincro then C3 Europe will likely have info on how to proceed for your specific area.
http://www.c3foundationeurope.org/If you have the opportunity to get Naltrexone instead, it seems to be better tolerated, especially when resuming it after being alcohol free for some time. The quickest and easiest route may be a private clinic and again C3 Europe will likely have more info for you on that. If you're in Europe, I understand that Naltrexone is OTC in France and Spain at least, possibly other countries as well. Certainly of the two, Naltrexone is the less expensive if you're not covered by insurance.