TRICHOMONAS FELIS

I have an issue with Trichomonas, does anyone know a vet who would be willing to prescribe Ronizadole in order to treat all of them at the same time?

It in large part depends on your circumstances (perhaps you could elaborate?) but in general, no vet would be willing to prescribe without examining the cat. Liability issues, fear of being sued.
On the other hand, if you have a long standing working relationship with your vet, he might prescribe the medication. Can you provide him with a stool sample?
If you are working with a rescue organization (you indicate treat "all of them at the same time"), then I'd go to the rescue organization. If these are stray/feral cats you rescued on your own (bless you!), I would contact the local SPCA, cat or dog rescue group, and similar oganizations in your area. I'd explain the situation and ask for a referral to the vet they use or one who is rescue/stray/feral cat savvy. (I "love it" when vets say bring in the cat who has fleas or probably worms even after you tell him he is feral and hisses when you even look at him.)

Thank you for your reply. I am a breeder and one of my cats is confirmed TF, however recent litters have been affected with TF (from various mothers) tested positive by their new owners. I have signed a Ronidozole meds waiver in order to treat the cat concerned but my vet will not treat the others.