You're looking more for someone experienced with WooCommerce and particularly the plugin you're looking at using (such as Stripe) and the API it provides for users.
I think the seven-day thing comes from the banking side (the bank puts a hold on the amount in the customer's account to ensure that it's still there when the merchant actually asks for it), so that in itself wouldn't to be something you can change. For orders that take months to fill, perhaps look at how the service you use handles pre-ordering, or set up a future payment. You might not want to be sitting on things like customers' credit card numbers for a long period because of the security obligations that come with that, but possibly you won't have to on your chosen platform.
If you were going to sit on all the customer details like that, then the fact is that it's not really an online system any more. You might as well not use an online payment system at all, and just process the payments yourself come spring.