I urge you to avoid the Planet Hollywood restaurant like the plague, unless you enjoy eating while simultaneously having your eardrums skewered with knitting needles and having multi coloured lights shone into your eyes like an MK Ultra style Michael Caine attack. Horrible fucking gaff. Honestly, the older kids might like it but you, the missus and the baby will be in hysterics with the noise and lights. And not sure if anyone's said this, but those Dinner Shows like the Pirates or Mediaeval Night, while the kids might like them, the food is fucking crap. Although we haven't been my sister said her kids loved the Wonder Works night.
Out of the "theme" type restaurants, you can't really go wrong with the T-Rex. There's a brilliant meteor show on the ceiling every half hour or so and loads for the older kids to see. The Disney character breakfasts and Cincerella's Castle are a great experience for the kids too. The Hard Rock is okish too, and the Nascar and NBA restaurants. all near Universal. Inside Universal, there's an old movie style restaurant where the tables are 50's cars, so the kids will probably love that too. And if they like Toy Story, there's the Planet Pizza restaurant from Toy story for them too in one of the Disney parks. Outside the parks, if your kids like hotdogs and milkshakes, the absolute best place in Orlando was Steak N Shake. The milkshakes were unbelievably nice. It'll be a cheapish too, maybe about $30 for the four of you, unless the baby is a hungry bastard and wants their own footlong chilli dog
If it's pizza they like, Giordano's is worth trying too. I think both of these places were near to the Buena Vista shopping mall. For you and the missus, The Red Lobster was nice enough for a fish place, and the best rib restaurant was Tony Roma's on International Drive if you like them, and Bahama Breeze was nice too.
And finally on food, if you want to save a few bob, the portions are fucking massive, even the kids ones. When we went the first time, our twins were only 7 and the eldest was 9, and none of them could eat a full kids meal on their own most nights unless they were really hungry after a full day at a park. We ended up getting 2 meals between the three of them on those nights. So depending how hungry your kids are, you'll sometimes only need one meal between the two older ones. There's also booklets with loads of money saving vouchers all over the place too. I wouldn't go out of my way to go to some of the places in the booklets, but if you're going to one anyway, you may as well save a couple of quid.
One thing I definitely wouldn't miss out on is one of the crazy golf places. Honestly. we had such a laugh doing that one night. I think Universal have opened up a couple as well this year. Not too expensive and the kids will most likely love it ( at least once!)
And if you've got the money for the Halloween Nights in Disney, honestly, it's well worth it. Absolutely fantastic night for the little ones and they'll get enough sweets to keep them quiet for a month. We didn't actually pay for the tickets though one of the times we went. We'd booked a table at Cinderella's Castle for a meal to coincide with the fireworks going off. Anyway, we rang guest services and told them that we wouldn't be able to get in with our normal 14 day passes, so they gave us tickets in the morning to get in for the night and told us that we could come anytime and may as well go and enjoy the park before our meal. Disney really are fantastic in our experience.
Mate, I hope you, Mrs Lenstar and the kids have a fantastic time