Help, cannot download software updates after HD erased!

Hello community,

Back story: I'm an ISM major, so I'm typically pretty good with computers. I've also played with some torrents and I understand the risks that come with them but I'm someone who does my research before downloading. Well, I have Leopard (running 10.6.3 currently) and obviously, I kept up to date all the way up to 10.6.8. However, I wanted to get Lion so I downloaded a copied version of the "App Store" version of OS X Lion. This is where the issue begins. I started downloading then in the middle of the download it says cannot continue, hard drive has an issue or has failed (something of that nature).

Issue: So, I erased my HD completely. It was the only option, especially since I lost my original Macbook Pro discs (2008 version Macbook). I erased it, even the Apple guy on the phone agreed that if I did this I should be good to go. Well, I'm not. I'm trying to get back to 10.6.8 so I can start recooping all my lost stuff but when it goes to download the combo update it always stops midway through saying "cannot connect to server" or "update may be corrupt," etc. I don't understand the issue...this may as well be a brand new computer again, no? I'm very computer savvy but this is just boggling my mind. I've searched hundreds of topics and nothing works. For the longest time I was getting "invalid checksum." SO, I erased my HD again, don't get that anymore, and now I'm back to the "update corrupt" issue.

Someone please help me, I'll be checking this every couple minutes all night. I couldn't get a Genius appointment until Thursday so I'm trying to just fix this myself.

PS: Everything works fine, I can download everything as usual, etc. I literally just cannot get any Apple stuff. I've even tried downloading it from the page to avoid the "Software Update App" and it still screws up.

Thanks!