With a focus on an aluminum extension, you're on the right track with the Streamline Redline brand. However, you should make sure that you like the design and function of the Quick6 pulley/cleat system. While it's a well designed unit, it does thread very differently than the Chinook or NP type pulley/cleat system. If you have a chance, you might want to rig your sail with it to see whether you like it.
Regarding the universal and 2 bolt deck plate, you might want to compare the Streamline and Chinook designs. While both companies have very sound designs, the Chinook version allows you to use the universal to tighten the bolts of the baseplate. This feature allows you to easily move the baseplate to work with different sail sizes without the need for any extra tools. Now, Streamline might have incorporated something like this in their design, but I'm somewhat doubtful about that. Overall, the 2 pin cup designs of both brands should be compatible with the Streamline mast extension, but if you elect to go with the Chinook universal, it's a good idea to check just to be absolutely sure.