Here are my thoughts;

You haven't been in since 2000, that's 13 years and a lot has changed, this might be the last family vacation for a while, once the kiddos get out of college and start making their own families. I would want to stay in the magic, for us you just can't beat it, the theming and magic that each resort has to offer. Using the buses so that you can all ride together, or if someone needs to run back to the resort for something it just a ride away. While there are vacation homes that are close to the parks, its still a drive to and from. My family prefers that extra time in the parks. Staying on site, also gives you extra magic hours, and a better chance of getting into the parks on day they could stop guest entry due to capacity.

I would suggest POR - they have rooms that sleep 5 - 2 full / they might have been redone to queen -beds, and a pull down, I suggest this as you said your not pregnant, so I am assuming that you still have smaller children that would be comfortable in the pull down. You can ask for room that has the door in-between, so that you still would have access to everyone. This way you would have 2 full bathroom, with 4 sinks, 2 TV's and the curtains will help with dressing and privacy for everyone. Another reason I suggest this resort is that you can use the pool and food court at POFQ, and they also have a boat that runs to DTD, which is nice ride. Also there is no charge for parking at the resorts, or if you want to take your car to the parks, no charge.

As far as renting a van, I would not, I would use my own cars, and any money that you would use to rent the van could go into oil changes, tires,and such for your own car, that way you are using your money for you and not the rental. Also this gives everyone a chance to ride with someone else and by switching cars. I would try to drive as far as Lake City, the hotel rooms there are a lot less expense than in Tallahassee.

I would try to get in and out before Christmas as this is the most expensive time of year. Also look for the free dinning offer, this way you can do some character meals, and other table service dining, after all Mom and Dad should get to enjoy someone waiting on them too. Also if you can swing it and if you do get free dinning, see what the cost to upgrade would be to DDXDP, it might be well worth it for your large family, The cost of dinning rise's quite a bit during peak times of the year. You might not be back for a long time so I would go for it. Also you would have everything paid upfront that's a wonderful feeling, and my for my DH it's a plus, so he can relax and knows that everyone can get what they want, and not worry about price.

As far as extra cash for your trip, there are lots of ways to make extra money, saving change, garage sales, plato's closet they pay cash for your clothes on the spot (more for teenagers), consignment shop, and Baby Consignment shops. Couponing for everything, Dog walking, Babysitting. I have a friend that buys a Disney Gift Card when she goes to the grocery store every week, She use's her saving form coupons for the cards.
GO for it, Have a wonderful and magical time
