I understand Silicone one's are becoming available in the States, but I cant tell you from Where.
Hose failure rates are not particularly high. most folk would not be willing to spend £ 100+ to get fixed up with replacement silicone (IMO).
BTW The 140 MPH Speedo's will be ready very soon, I have to road test one in Delores. They will be available on the basis of converting tour own.......prices to still firm up.
Chrispy