Typically, poached pears are cooked in a mixture of wine, water or fruit juice and sugar, but due to the high sugar content of the cider -- not to mention the decadent caramel topping -- these little guys don't require any extra sweetness. For a simpler, sans-caramel option (what fun is that!?) you could add a cup of sugar to the poaching liquid and reduce the liquid, itself, down to a sauce once the pears are removed.
Regarding the type of pears chosen: most recipes will recommend Bosc pears, which hold their shape nicely, while Bartlett have kind of a bad rap for falling apart. I've made this with both and didn't find the Bartlett to be exceedingly difficult or mushy. Good ol'
DL isn't a fan of Anjou, so I'll take his word for it. :) Regardless, the fruit should be ripe but firm, erring more to the side of underripe than overripe, if you're questioning it.