Getting ready for IMAZ 2013, need to get better at running!!

Let go of any time goals for your first IM.

Run more frequently usually helps folks more in IM  than what the distance is of their long runs.

How many times a week did you run while training for your HIM?

Have you done any stand alone running races? If so what was your time?

I like Higdon's marathon plans.

I used his 3 day a week plan as a base for my IM plan in 2011.  I added swimming and cycling to the plan and it worked out well for me.  I favor running, though, over swimming and cycling.

Most IM plans you will find have the running built in.  Unless you want to build your own plan, why not stick with a prepared plan?

You have a lot of time to prep before IMAZ 2013.  Can you work in a plan to train for a couple more half marathons in the first half of next year or even a full marathon to get that base built up and to feel more confident?

I'm not the faster runner in the world but I have always kept a consistent run base - that gives me the confidence I need to know that barring a major meltdown on the course, I can get the marathon part of the IM done even if I have to walk part of it.  I'm comfortable with the distance and the time and that really helps. 

So maybe try to do that the first half of 2013 and then switch to your IM plan when it starts in the summer.

My suggestion would be to not downplay the importance of riding more.  I did IM Arizona this year and when I do my next IM I will focus on the bike even more than I did this year.  By way of comparison to the info you provided, for Jan-Oct, I rode over 4500 miles.  My longest runs were in the 18-19 mile range.  On race day, however, my run started to fall apart at mile 10-11.  I had run over 10-11 miles dozens of times in prep for the race, so at that point, it wasn't a lack of run fitness that was coming back to bite me.  I needed to get even stronger on the bike, and/or alter my pacing on the bike in order to minimize the fatigue starting the run. 

Yes, I would have liked to have had more run miles in my legs leading into the IM, but I also think that the importance of being incredibly strong on the bike coupled with really nailing down my nutrition would have served me equally, if not more so, for the IM run.  That is not to say you can get away with not putting in the work on the run, but, as I said, I would not downplay the importance of bike training to set up a good run. 

One other thing that was a challenge for me was nutrition.   I thought I was taking in enough on the bike, but I think I needed to do more.  When I started IM training, towards the end of long bike rides, I would not want to eat any more.  That was fine for a stand alone ride, or even for a short brick after, but I think it came back to haunt me when you have a 4.5+ hour run coming after a 112 mile bike.  I got better at it as the training went along, but I still did not execute perfectly on race day.

Good luck training.  IM Arizona is a great event.

Begin running (almost) every day.  5-6x per week, all easy/comfortable pace.  Develop one of them into your long run ("long" will be determined relative to the rest of your running).  This is a good resource.  Start now, as 5-6 runs may become tougher as you get into your IM training.

Edit:  Do NOT do a full marathon between now and then.