You might find that buying vine eyes, tension fasteners and wires is as much as the tellis - so check first as it's easy not to realise until you've got to the till or after the event (voice of experience there!).
Pyracantha shouldn't need anything to support it. They usually come on a cane, lean this towards the fence and you should be able to let the plant do the rest.
Sweet peas are fairly light so can be supported on pea netting or using string. Advantage of latter is that when the seasons over you can just cut it all down saving you untangling and pulling dead bits off a more permanent structure.