Try to select carbies that are one barrel per cylinder, this way you will avoid all the issues that arise when you use a single barrel carb on each head, webers and dellortos are a very reliable carby and I have three sets in total , they stay in tune as long as you have the linkages sorted, with a mild 1776 I would run a set of 40mm idf webers, these should have 28mm chokes fitted standard, if you put larger chokes than 28mm in you move the power band up from the bottom end and add to the top end, you will loose torque if the chokes are to large for your application, you would be able to use a vacuum advance distributor with these carbs, you need to think about what other mods you would like to make when you build the engine as these will have influence over the final set up of the carbs. keep in mind that you could build a 1915 for the same money as a 1776. try this link.
http://www.aircooled.net/vw-carburetor-tech/
