Since you ask for information; here it is. No there is no reason to have throttles,(a word that means; valve.), such as butterfly valves in the runners between the head and the Plenum. If they did have throttles in them; they would then be (throttle bodies); otherwise they are intake runners. I understand what you're saying about tubular runners entering the side of a plenum; and short tubes underneath the runners close to the head for the injectors. If you like to work in metal and can braze or mig weld; either one will be fine, or have a friend who can, you can certainly do this. If the mouth of your runner that mates to the head is a tiny bit smaller than the head/gasket that will be fine. Larger than the gasket/head hole is not good. One of the advantages of supercharging is that many details that are important for non-supercharged, or NA,. engines, are not significant for you. You don't need bell mouths on your runners where they enter the plenum. Exhaust tubing is available in 45degree pre-bends which are usually pretty usuable. What's wrong with the manifold that comes with the engine? Unless it's a carburettor manifold it will work real well. I reccommend the 6" truck exhaust tube for the plenum because round shapes are desirable and it"s about the right size. If you squash it a little so it's oval it will be better. Then the runners will be going in one of the long sides. Your re-cycled throttle body just bolts on to an end header that you weld/braze to your squashed tube. The six inch tube plenum should extend several inches beyond the front and rear runner entries; if possible; if not don't worry. This is kind of the easy part of a turbo-charging project; I'm sure other people can advise you on a specific type #turbo to use; which I know nothing about. The most important single thing you can do is to inject a 50%methanol, 50%water mixture into the intake of the turbocharger; this is extremely beneficial. It can be very cheap and simple' an underhood container with a small tube line running to the turbo intake; from the bottom of the container; and a small flex lilne running to the intake manifold, with a one way valve in it is all that's necessary; The boost pressure in the manifold will blow fluid at the impellor in proportion to the boost pressure; at cruise conditions there won"t be any positive pressure in the manifold. The container will have to be able to withstand your boost pressure. Early model VWBug windshield washer fluid containers are ideal; I don't knkow if they're any left; they have a tire valve in top of the, (heavy)plastic vessel sothe owner could pressurize the thing at the gas station with the tire hose; and then later on, get a couple of squirts out of it when driving; I"m not making this up. well have a Fosters for me. cheers Jack.