OpenHAB - Electricity / Gas consumption - Energy Provider Smart meters

With regards to own power meter in distribution box that’s probably the best solution for now till there are some proper (open- read only) “smart meters” available in U.K. What’s the best reliable energy power meter (electricity) I should consider installing in ?
Guessing it will be difficult to get anything for gas meter as I can’t really tamper with it?
I like the idea of counting LED flashes, I seen this topic before and seems to very interesting. I had a look at our meter today and there is red LED flashing frequently on the meter so I may consider looking into this option here. I just wonder how reliable this solution could be, so if anyone could provide some feedbacks that would be great.
Our gas meter is indoor under stairs with quite easy access , however our water meter is located outside property buried underground on public footpath so I couldn’t run any data cables back from it unless go for battery only operaring/wireless. Also it’s always underwater in rainy days. I just wonder how water utility company is obtaining data from those meters. If I remember it correctly, this unit has radio link so when they sent guy around to record usage he doesn’t need to access the unit at all but I may be wrong on that.