I use Podomatic for the podcast now. Doing a live show ends up costing money I don't have to spend. Podomatic has a free account that should suit your needs just fine. The only reason why I had to pay was because I uploaded so many shows at once and used up all my bandwidth. If you get in on the ground floor you should be all set.
Also, I will listen to this next week when I get back home. Any other support I can lend let me know.
As for recording calls, I use Skype and use an add in called call recorder to record the calls. Feasibly you should be able to have people call in to your shows without too much trouble. The way you want to set it up sounds like you are going to need to do a lot more editing than we have to do. Which isn't a bad thing if you have the software, patience and time.
45 mins to 1 hour is the golden time for a show. Anything longer and it loses it's appeal.