Attaching Deck to House Options

Can you help me think this out?
I plan on building a screen porch at ground level and a deck on top of
the screen porch on to the end of the house. The deck would be as long
as the end of the house (24') and 11 feet out from the end of the
house and supported by 4 footing/piers and beams. The deck will be
level with the second floor or about 8' above the floor of the
screened porch.

The end of the house is 24' and consists of one family room with 2
bedrooms on the second floor. The end of the house sits on a footing
with a 24' concrete foundation. The end of the house first floor
wall is 2x4 framing resting on the concrete foundation. The second
floor (2 bedrooms) have 2x8 joists who's ends are attached to a 2x8.
The 2x8 and the joists rest on the 2x4 framing from the first floor.

. . . .

In the center of the first floor 24' family room wall is a 9'
three light sliding patio door of standard height. The header above
the patio door is a double 2x8 header. There are no other openings in
this lower level wall.

Can I get away with attaching the upper deck joists with a 2x8 attached
to the second floor 2x10 sill? And attaching the screen porch joists to
a 2x8 and attaching the 2x8 to the first floor framing near the
foundation?

Alternatively, I would pour 4 concrete footings and piers next to the
existing foundation to support the deck and porch load. I would then
tie this into the existing structure at the deck and screen porch
level.

I like the latter idea, in essence. Build it as a compeletly
self-supporting structure. (Which is going to take more than
four corner posts, I suspect) And then attach it to the house
to keep them from shifting around relative to each other.

Is there an alternative I have not thought of for supporting the house
side of the porch and deck?