Hi,
Our son is 13 years old and is autistic/non verbal.
We have travelled to Florida many times and have no worries about doing so now.
We have found Joshua's patience levels have improved over the years when waiting to go on a ride/attraction, to be honest it is something I would encourage you to stick with as I am sure you will find an improvement though perhaps not in the short term.
Most parents with special needs children just want to do what everyone else does, and that includes waiting in lines. However, it's just knowing when not to push that too far.
If the wait time is up to 10 minutes or so we are happy to wait and generally so is Joshua.
It is when there are longer wait times, pre-shows or attractions that take longer to complete where it starts to get more complex.
There is a good FAQ on here that talks about the GAC - Guest Assistance Card, which I recommend you get, this can help in reducing your fears, helps CMs recognise your needs, and can mean shorter wait times if preferred.
I would strongly advise trying to build up your child's patience levels, like I say it's just knowing when to avoid pushing that too far.
To be honest we have never sought advice from 'touring plan' experts, partly as we have been so many times now we feel there is no need. Depending on what time of the year you are going I would also advocate visiting at cooler and quieter times of the day.
For example at Magic Kingdom you can increase your chances of getting on the attractions for little one's if you get there first thing in the morning, queue times will be shorter, you also have the advantage of then having done a few of the rides - which means you can take things at a more leisurely pace and the pressure to rush around and see everything is less intense.
Are you planning on using a stroller?