Ebay MNKE 26650 Batteries

I bought a Ultrafire LW-12L2 torch after 18sixfifty said it was a bright torch , I also bought some Trustfire flame 26650 batteries for it before his main review came out
So I bought ones with protection ,which when fitted fully charged last a few secs then the protection kicks in
It works fine in low and medium just not high although after running batteries for a while it seems to last longer before tripping out
However the brightness is not what I thought it would be (7200 lumens) it is brighter than my SRK ( 6XLED DX one with braided springs FET swap and uprated wires) but no where near twice as bright.
So I think my batteries just cannot supply enough current for it so I need some better batteries

Would flat top be suitable for series use or does it have to be button tops?

I have emailed Richard at RMM about some KingKongs for it just waiting a reply but I saw these on Ebay

2x MNKE IMR 26650 3.7V 3500mAh 60A HIGH DRAIN Li-Mn RECHARGEABLE BATTERIES

Which look good but I’m wary of anything on Ebay, it does have fast delivery though and ideally I would like them for next weekend as I am going away to the Lake District to a wood cabin in the middle of nowhere so it’s a good opportunity to play with the torch.

Has anyone used this Ebay seller? Or know anywhere with fast delivery to the UK for genuine 26650 batteries?

Thanks