Redoing my backyard, need suggestions

We are having our backyard completely leveled and new top soil put on. When that's all done I thought it would be a nice idea to do some backyard movies. I'm looking for suggestions on equipment,

- a 720p projector
- a way to do the sound wirelessly

My brother just installed the sonos amp at his house for music and it works great. I will have. 2.1 receiver in my house hooked to speakers that are connected outdoors to the house. I want to project on the side of the house and I thought doing it from my iPad using Plex to access my movies would be the best way to do it. I can do 720 from the iPad easily over wireless. My only concern is how to split the audio?

Well we're going to spend a LOT of money on redoing our yard that this theater idea is a last minute thing and is not really in the budget. I wanted to just get a projector and run an extension cord out to set it up when it's needed. The only issue I'm trying to figure out is how to wirelessly send the audio to the receiver inside.

Can anyone suggest a good sub $500 outdoor 720p projector? I don't mind if it's used either.

My brother can get me an Epson 710HD for under $500 as an open box at BB. How would this projector fair outdoors? Is 2800 Lumens enough?

I guess I just have to figure out if $499 is worth it, if I'm only using it a few times a year.

Hey all I want to renew this thread. We now have our new fence up and will be seeding the backyard again soon. We'll be hooking up outdoor speakers in the next two weeks for my son's 2nd birthday. I thought it would be cool to show a movie later that night for those that were still around. Have any good deals on projectors popped up in the last month or so? Keep in mind I will only be using it a few times a year and outdoors. Also the source for the movies will be an iPad Gen 2 so 720p is the max resolution it'll do.