experimental crocodile phonology questions

As far as the phonology, I have a decent grouping

Flaps & Trills: 4, r, r:, r`, R\, R\:
Fricatives: T, T: D, D:, s, s:,  z, z:, S, S:, Z, Z:, s`, s`:, z`, z`:, x, R, R:, X\, ?\, h, h\
Laterals: r\, K, l
Approximants: j

It was sugessted to add in K\, X and G...

The vowels are
i, i:, i_k
M, M:, M_k
e, e:, e_k
7, 7:, 7_k
a, a:, a_k
A, A:, A_k

for a nice front back vowel harmony

And we have 5 tones..

High - 1
Rising - 14
Mid - 3
Falling - 41
Low - 1

As one can see, by the reptilian sounds, we are dealing with no stops, no nasals,
and no lips which means no bilabials..

Here is my question...

For a good hissing string of sounds..I was inclined to make my s, r and z sounds as initial

But.. What I need are ideas on a good syllable structure..

I was thinking of CV(V)(C), but the initial c doesn't seem to give a good nasty
reptilian hiss to the syllable...

OBTW: for those curious as to the race of said critter.. I was doing this for my
sentient crocodiles..