I'm not sure you've got a particularly solid starting point, though I may be misunderstanding your post and components.

I also know that once you get a new bike, you want to use it.

My suggestion would be to buy a decent bike aiming for a good quality frame and reasonable components, then slowly upgrading them as you ride and can afford them rather than buying the IRO frame and (presumably), using the bits off your existing bike.

Your existing bike can be kept as a spare (for those days when the weather is dreadful or you'll be leaving it somewhere less than safe) - everyone should have a beater that does the **** jobs, or it can be sold.

I'd steer clear of Craigslist unless you can take someone with you who really understands bikes and bits or at least has a keen eye and the balls to tell you not to buy something.