I like the plastic tube that resembles the plastic vacuum hose. I think it is what you have. Is the NEW Opti digital throttle & shift?
If not the rigging tube might be too full for the hydraulic hoses to pass thru.
I recently purchased a Sea Star hydraulic steering unit. The hose was expensive but it came to the length I ordered and has a fancy black anodized fitting for bulkhead mounting. I have also used the thru transom style that uses a piece of brass to pass thru the transom. It requires two smaller lengths of hose to reach to cylinder.
Bulkhead fitting built onto hose.
http://ww2.seastarsteering.com/PDFs/971715-E.pdf
Thru transom:
http://ww2.seastarsteering.com/FITTINGS/fittings.htm