Ted,
I am not an expert, but this is what little I know, and my opinion:
I went tapeless to get rid of interlacing and 1080i. I was immediately glad, and would never go back to tapes. The storage problem is easily solved by multiple USB hard drive backups, and is still way cheaper.
I just bought an EOS 5D because I needed a broadcast quality image. I would think a 7D or even a T2i would work, depending on your requirement. I needed the full frame on the 5D, because I have a very tight space. I need full body shots at 7 feet to lens, and I could not get that from either a 7D or a T2i.
The 12 minute limit is an issue. I am keeping one HF S10 for when I do talks in front of groups (which tend to go on for a couple of hours). That way I just start the cam, and forget about it until I am done (one less thing to be mindful of makes for a much more relaxed presentation). Also, the T2i tends to overheat and shut down after about an hour.
If you are adventuresome, you can always use the HDMI out port on an HF S10 or HF S11 to capture raw. This can be done with a Black Magic card, but the AJA cards are much higher quality. That will blow away even a 5D. There is also the Convergent Designs Nano Flash unit, which captures raw.
The issue with AVCHD is that it compresses so tightly. It is like reducing a picture of the Mona Lisa 100 times on a Xerox machine, and then blowing it back up. No matter how fine the initial source image, that much compression and re-expansion muddles it up somewhat.
HDV and interlacing have their own issues. I am not an expert in that area. I do know that they make some dandy HDV broadcast quality cams, but I would think that an HF S10 or S11 coupled with a Convergent Designs Nano Flash unit recording in raw would blow it away.
Perhaps someone else might have some better experience with that, and they could tell you for sure.
Norman Willis
http://www.nazareneisrael.org