Well, you can ignore the Cardioid set of presets as you're only using one box - they are used when combining (usually) 3 boxes in a certain way to reduce LF spill backwards from the PA.
As for the others, it's really a matter of taste - get them set up at a practice and try them out for yourself.
A couple of general thoughts do occur though...
1: using the Extended Low presets may give the perception of more bass even at more modest volumes, but it also uses up a bit of headroom - so if you're trying to run quite loud, this would be counterproductive. It's likely to result in the tops outrunning the bass bin given your 2:1 ratio of boxes - again, if you need to run loud.
2: the higher the crossover frequency you select, the more work the bass bin does and the less work your tops do - if you were really trying to max out the volume you can run at and still keep the tops nice and clear sounding, you'd probably get slightly better result using the higher crossover therefore. However, for small to medium wedding gigs, I'd imagine you're not likely to be pushing the rig hard enough to need to worry about that.
3: remember to run your mixer's L & R outs into the bass bin first, then jump up to the tops, so that the crossover between the 2 is correctly handled - otherwise your tops are going to try and play the whole spectrum including the low end.
HTH,
David.