I got a pretty cheap torch off amazon that does the job. It's very similar to this http://www.amazon.co.uk/LingsFire%C2%AE-Detection-Blacklight-Flashlight-Counterfeits/dp/B00YRZ2X54/ref=sr_1_4?ie=UTF8&qid=1435878806&sr=8-4&keywords=uv+torch+scorpion. It works up to several metres away. For Euscorpius you're mostly going to be looking along old walls and buildings so you won't need a huge range on the torch anyway.
For Buthus occitanus I would recommend flipping rocks during the day time. When I was searching for Buthus ibericus in Portugal, this method gave the best result (to be honest I saw nothing at night using a UV torch). Rocks around the size of a football and above gave the best results as they were big enough to retain a little humidity under them. Be careful if you do find B. occitanus, though. They are very quick to sting.
Good luck hunting.