Does anyone receive services and supports for secondary students who are both LD and gifted? How are they being served esp. in the area of Executive Function in AP or IB courses... Did you need an IEP or a 504 plan to get help?

Hi Connie, yes, they will most likely need at least a 504, if not an IEP, but get ready for a fight!
I am a Connie as well, and I have a dual exception son. I will not go into all the details, but yes, my son has a 504, and it is absolutely necessary. My son was identified as gifted first, then when the problems that were initially said to be stemming from 'boredom' because he was gifted persisted and actually intensified with the rigors of the gifted curriculum, we paid the out of pocket for additional testing. Highly gifted with learning disabilities, specifically, Dysgraphia, Visual Processing Deficit and Inattentive type (non-hyperactive) ADD. I still feel there is more going on, as my own research and personal experience shows a lot of the symptoms point more toward executive functioning, but I digress.
Here's the issue, or at least what I have encountered,, these classes, AP, IB, Gifted etc., they are already differentiated (as the gifted teachers and school administration eagerly point out and defend). They are geared toward a higher achieving, higher ability student. In my personal experience, the teachers and administration of the gifted curriculum are, as a majority, unwilling to provide accomodative services because, as they put it, the classes are already differentiated for a particular type of student, and it is practice if any student is unable to maintain in the advanced level, they are returned to a less rigorous curriculum. This is their understanding of their differentiated curriculum, and it is difficult to get them to understand the implications of a Dual exceptional student.
The advanced classes are designed for students who are naturally able to keep up with the more difficult work load. Here's the catch 22 though, when a child is identified as gifted, with substantiating evaluations, the gifted and/or advanced curriculum becomes the "appropriate" education for that child under FAPE (Free and Appropriate Education). Therefore, if the child is discovered to have learning disabilities, the child is entitled to have those disabilities accommodated so that the child is able to perform commiserate with his peers (his peers being other identified gifted/advance placement students who do not have a dissability). 'WritesLaw' is an excellent on-line resource for parents of Dual Exceptional students seeking accommodative services, as it outlines the misconceptions, misunderstandings and misrepresentations of the educational laws and gives clear founded evidence on the unique needs of this category of student and their rights to be accommodated. I highly recommend that you check out the 'WritesLaw' site, and I personally suggest that you not wait until your child is struggling, or is being removed from programs, before beginning the process of getting the accommodations he/she needs to succeed in the classes that are appropriate for them. Hope this helps.