I only use E3Dv6. I don't ever use the lite as I think it has the teflon tube still in the hotend limiting the max temp to 240 -250 deg C. All metal V6 hotend is good for 305deg C
All metal is what you need if you are looking at non genuine V6... as in if the add says all metal you should get that.
A tip: non genuine or copy E3D v6 are fine and I do use them but you need to make sure the heatbreak centre is drilled out to 2mm I have found a lot of non genuine less like 1.8mm and they will jam not straight away but as soon as you have a heating problem or filament problem. E3D realised this and increased their hole early on.
If you want to save money but want best as possible... only buy genuine E3Dv6 heatbreak and nozzle. Then buy non genuine hotend block and finned body. You will save about 50% of you money especially if you invest in a few.
If you want to go a step further... if you look on Aliexpress you can buy non genuine E3D Titan Extruders. They are less than half the price and some have free postage so another $30 saving. I have been using one for 2 months non stop and I can't fault it at all.