your best bet is to try the Caprisport style stuff...

you can get recon front Granada Calipers for about £30 a side, then you have two choices...

use the 260 mm setup if you have deep enough wheels, or 283mm if you have 15inch wheels.

Next you have to machine down the hubs so the disc ( 260 = RS Turbo, 283 = 2wb Sierra Cosworth ) fits over the hubs - you can get a machine shop to do this for £20. Then fit sierra wheel studs to the hub.

Then buy a bracket off caprisport and away you go.

I expect you could get the conversion done for just over £150 and the brakes will then be awesome.

I have 283 on the front of my 24v capri and bl**dy hell does it stop quick.

This brake setup allow you to brake quickly with out having to resort ot locking up. Front wheels locking is not an indication of good brakes. Rapid deceleration without lock up is good.