I am trying to locate a power supply for a Medion Akoya 6815. Every model I seem to find gives the laptop a small current that causes a bit of a tingling/vibration feel on the metal sections. I am assuming I shouldn't trust these?

I wouldn't trust such power supplies, do you feel the current everytime you touch it or just the few seconds when you plug it?

Quick ebay search: http://www.ebay.co.uk/itm/MEDION-Akoya-P6815-GENUINE-LAPTOP-CHARGER-ORIGINAL-ADAPTER-POWER-SUPPLY-/251347967835

First of all : read the specs of every power supply. You shouldn't use one that isn't a perfect match (Volts, Amperes) - at the very least not for a prolonged duration (you will kill your batteries faster and so on).
Then, if you actiually use a alledgedly compatible PSU and if you have a feeling that your frame is not connected to the ground, you should worry indeed (but I am not sure if that's what you are implying).

That is the exact seller that I have received from my last three from. They are the same spec, weight and design as the original that came with the laptop. However since my replacement died a few weeks ago, I cannot find a replacement that doesn't cause that little minute tingling.

What are the chances that Medion's latest range would support the same specs as the older models?

I've been reading online about using a 3 pin charger, I'm not sure how the wall plugs are in UK but if you can do that it might be worth a shot.

3 pin socket plug? That is our default.

Is the charger plugged in with a 2 pin or 3 pin cable?

three pins, charging right now.