Any hat will work fine. The bug might be harder to find second hand, I use to be able to get them everywhere . Bird probably easiest to find. I like the bug for lots of reason. easier to see around and over. Just looks nostalgic. Plus was first injection I had. Bug flows 2300 cfm and bird twice that. My old bug was most consistent thing I have ever run. If new to injection keep a simple setup and it is easiest thing in the world to tune.
