I'm checking prices in TheCubicle and Lubicle silicone is 3 times more expensive than TheCubicle's ($10 for a 5cc syringe opposed to $3.89) so, unless somebody tells me that the difference in prices is worth it (quality & durability-wise), I think I will get one of each (wt 1 & wt 2) from TheCubicle brand, just to stay on the safe side. Currently I have (appart from the already mentioned wt3) also wt5, which I have used to lube the cores of several cubes already with very good results.
I am assuming that the silicone syringes, if correctly closed and stored can last for years so, even if wt1 is too fast for me now I will use it in the future, I hope. And if not, 3-4 bucks is not a big loss.
Answering more directly to your question, if you don't want your cubes too fast I'd say you can go with wt 2 or 3 but it depends on how fast you are. As we were discussing, I find wt 3 a bit sticky and I average 21-22 seconds but it also depends on personal preferences and the amount of lube you put (too much = gummy).