Winter Marathon Query

I am queuing up Part Two of my little "Aching Backs" series. This will be the one in which I detail my physical therapy program as it stands right now.

First, however, I need some educated opinions.

Right now, I am signed up for this October 21 race:

I'm not exactly training for it yet, but I guess I'm training to train.

Though I may not be allowed to run at all until mid-July, I'm still planning to run Detroit. But it's probably not realistic to think I can run it fast enough to beat January's Houston Marathon PR of 3:53:28 by at least 10 minutes--which is what I need to do to qualify for the Boston Marathon in 2014.

So I need to sign up for at least one more marathon before I turn 40 on January 21. Given what's going on with my back, BQing before that date (which was the entire premise of this blog) may not work out. But I'm not going to quit trying. (And if I don't make it this winter, I'm STILL not going to quit trying, so don't think that of me!)

My question is this: WHICH winter marathon should I sign up for?

As a sub-4-hour marathoner, I am granted early and guaranteed registration for the Houston race next year on January 13, a week ahead of my birthday. Early registration opens next Tuesday. But a lot of smart runners are signing up for the California International Marathon, a month and a half earlier on December 2. Looking at the course, it's tempting:

Hard to beat that profile....

Here are the pros and cons:

Houston Pros:

1) Six extra weeks to recover from Detroit and train
2) Familiar course--this would be my third time at it
3) Lots of friends in town; the support in January was amazing

Houston Cons:

1) Remember that weather in Boston the other week? Yeah, that's quite possible in Houston, even in January.
2) Not as fast a course
3) I'd have to train over Christmas again; I was hoping not to have to do that this year

CIM Pros:

1) Great course--see that chart again; according to Runners' World, it's in the top five of Boston Qualifiers
2) Good chance of nice weather; average temps are in the 50s
3) No training over Christmas

CIM Cons:

1) Not as much recovery/training time after Detroit
2) I know no one in Sacramento, though I'm sure I'll know some other bloggers running it

Of course, I could sign up for both races. This is also tempting. But it's a lot of money out of my family's till, and I'm not sure I can expect to do three marathons in four months and do any of them well. With my back an unknown variable, I need to do the right thing with this.

What's your opinion?