The problem you see is a compatability problem. Since I do not know what kind of application you are implementing I will give you a summary of the options you have below.
The Analytics SDK is compatible with the following high tier research eye trackers: Tobii X60/120, Tobii T60/120, Tobii T60 XL, Tobii TX300 and the Tobii X1/X2.
The Tobii PC Eye Go eye tracker is compatible with the following SDK’s: Tobii TecSDK, Tobii EyeX SDK and Tobii Gaze SDK.
What SDK or eye tracker you need depends on what kind of application you want to develop.
The Analytics SDK license allows for developing analysis and research kind of applications that process data from Tobii hardware and software, where eye-gaze data may be stored locally and later be processed and analysed.
The Tobii TecSDK license allows for developing AAC (Augmentative and Assistive Communication) applications for Tobii hardware. For example, with this SDK you can create an eye controlled application that uses eye-gaze dwell to click on buttons.
The Tobii EyeX SDK and Gaze SDK licenses allow for developing eye-gaze interaction applications for Tobii hardware. This include AAC but exclude analytic applications. For example, with these SDK’s you can create an application or game that uses eye-gaze as an input for interaction (often in combination with keyboard, mouse or some other input device), and you may filter the eye-gaze data live dynamically to achieve the interaction you want, but you may not store and then later analyse the eye-gaze data. The EyeX SDK is the high-level SDK for eye-gaze interaction applications that should be able to co-exist with other gaze-enabled applications running simultaneously on the computer, the Gaze SDK is a low-level special purpose SDK for stand-alone applications.