I am planning a trip to Europe for 3 family members to Europe in summer of 2013 week of July 4 and only two are old enough to apply for cards. Since tickets are available 11 months ahead of time, I am thinking I have 2 months to get the miles together.

My strategy is:

2 Us Airways cards - 40kx2 miles, no purchase
2 Chase Sapphire Preferred - 40x2 miles, $3000 minimum spend in 3 months
1 Chase Ink Bold - 25k miles up front, 25k more later on with spend.

This will yield 185k US Airways miles (I can front them the UR miles and get them back later if the sapphire doesn't post in time) and use Star Alliance partners to fly. I then want to do the following trip:

NYC-LHR (train from LHR to CDG as it's way more convenient) CDG-VIE (destination) VIE-NYC

This should cost 180k UA miles. My main question is whether this can be obtained using the US air miles provided it is available on United for 60k miles and whether this is a legal routing according to US Air award restrictions (open jaw OR stopover).

Good plan or is there a better way to get the 3 tickets? They actually have about 160k AA miles right now, but I can never find good award routings on AA in middle of summer so I'm thinking getting the US Air miles is the way to go.

I then have the rest of the year to work out hotels.