FYI, 1968 and wlp002 (Fullers) are the same strains.
1728 and wlp028 (McEwans) are the same strains as well. So this narrows it down a little.
I would use the 1728/wlp028 (McEwans) yeast as it usually does a great job simply due to the fact that there are typically more unfermentable sugars in a wee heavy than a normal ale, also the McEwans yeast was raised on scotch ale (wee heavy). The yeast tends to add a slight smokey flavor so if you don't like that you can use any cleaner english strain.
It sort of depends on your recipe though, I like to keep all my scotch/scottish ales with a simple grain bill, 2row and roasted barley.
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