Definitely not me duplicating the posts.  Took too much care on the last one and hey presto - you get it twice.  Sorry.
This is by way of a test so apologies in advance.

Soja-saane is about the only one I know of that's vegetarian and "double" in consistency - but it really doesn't taste very nice at all.  I have in the past used Lacto-Free's  cream, which will whip if you thicken it with gelatine, but that's then not vegetarian - although you could try agar-agar? 

Alternatively, if you have 3 days to spare (and you're lactose intolerant not casein intolerant!) you could put 4 tbspns buttermilk and 1 litre double cream into a yoghurt maker, ferment for 36 hours, chill for 12 hours, then use as a whipped fermented cream (the fermentation digests the lactose, you see), and turn anything left over into a fermented butter in a food processor.

Thanks all for replies