It's a good lesson and one I should remember.
No calendar based plugin, yet. I've not found one that will integrate nicely with woocommerce products. I think Woo are working on something but it might be a while.
At the moment I'm using the product quantity as a selector for the number of nights stay, attributes and variables for the individual rooms in houses, and users just select a date range in the checkout/billing form to cover off the dates they will be staying. The date range isn't linked to the number of nights selected of course, which could be a lot smoother.
It's made even more complicated by the fact that the client is an agency - sometimes the customers first choice may not be available so they have to add a selection of homes to their "list" (cart), but this requires me to hide all of the subtotals etc too, as they will only be billed and charged for one of thier selected homes when the booking is actually made by the client.
I knew it wasn't going to be easy - especially as I'm no coder (!) - but anything is doable when you put your mind to it. Oh, and when there's a thriving community willing to help out occasionally haha!
You've got my email, let me know if a bit of freelance help here and there is of interest and enjoy the beer ;) Thanks again man, it's looking almost perfect now.
I dread the upgrade to Woo2.0 but it'll be better in the long run I think, so many new cool features coming that I can take immediate advantage of.