MX-5 Mk2 1.6 4-2-1 manifold

[Rusty-C]

Per the title really, I'm looking for a 4-2-1 manifold for my Mk2 MX-5 1.6, but can only seem to find one for the 1.8. Does this mean going down the custom manifold route and if so how much is that likely to cost? Any wisdom appreciated.