The sensor Curtis / Immortal Hobbies sells I think is still being made but I have never ordered one, I think Dean knows more than I do. Impact ones are good, and with a bit of modification you can get them to fit Tamiya / Clark bases too.

How are they range wise? I've been whining at meets because my laser-guided tank IR works 40-50 feet vs my OWN tanks with Tamiya apple... but I can't hit those damned HengLong sensors from 8 feet away >< Bwahahaha. Emphasis on whining.