Maybe define "best" a little better? It looks like the F1, IRL type engines have individual runners and throttles. Tuning the length of the runner would be easier that way with the common plenum area above the throttle plates. If I was looking for maximum HP, I'd look into following their lead. The single TBI on a single plane intake looks cost effective, but probably is not the optimum power wise. Since you are using the turbo approach and from what I've seen of your car, I'd say you are well below F1 budgets (as we all are). I was told by a guy at Rousch back in 1998 that the injection near the head was done for emissions, not max. power. He said for maximum power the injectors get moved up to the top of the runner. I've seen an F1 engine with the injectors above the entrance and fogging the fuel in on top.