This is a common question. You might want to search for similar threads that had alot of responses.
You could possibly cut down the original front Fairing cage, so there's just enough left to mount your original Clocks, plus adapt for a new Headlight.
There's SO MANY aftermarket motorcycle headlights on ebay / amazon etc. You'd usually pickup some generic Fork clamps to hold the Headlight in place, one each side (for a side mounted headlight).
Aftermarket Speedo's too, usually come with a 'universal' clamp to attach to your Handlebar. So no problem there either.