IMHO, anything over 71% depth starts to "show it". Could be just me, but I'd go with the shallower diamond. Of course, I'm sure Gary and Dave Atlas will recommend you get sarin results, as that's where you'll really find out how much this thing will shine.
Diamond #1 will be set in platuinum with .71 twct of channel set baguellions (I'm not sure if that is the correct spelling but they are faceted baguettes). And a v cornered head.
Diamond #2 will be set in a 18K White Gold setting with platuimun 4 prong head and .8 txct princess cut chanel set sides.
The prices listed above do not include the setting. Each stone is at a different jeweler.