At the moment im using either a toda tep tegiwa manifold ( altho thats on the road car at the moment) and a 5zigen, both 4-2-1, and fit very very well on the type r block, unfortunatly im using a b16a2 so ground clearence isnt as good, but alot better than a dc 4-1 would be.
Im using Selholm suspension from dmrr, and its superb, very comfortable as I use the car for work lol, but on a stage the harder you push the car just comes alive, totally predictable and effortless to drive.