510 pre-filled seem to be coming up now, but as Dormouse suggested using 808s with a 510batt-808 adapter gives a lot more choices.
One suggestion -- if vapor4life you may want to use their nominally warmer WOW cartos, not coolcarts, to get lower resistance (warmer, more vapor). The same applies to other vendors offering prefilled -- look for their lower resistance/warmer cartos.