Any DIY experts on here?

[fazersharp]

the large space is hard to get a good finish. Although that could be my lack of skill

I supose it does take practice.
Another way is to get a lenght of bull nose cloaking upvc it will be about £3 for 5m 3mm thick x 40/50/60 mm wide - whatever you need and the cut out the sink profile where it drops off on each side and the sitck that on with silicone. the trick for a good silicone finnish is mask everything off except a 3 mm overlap and smoth that with your finger - wait for it to go off a bit and then spit and finger again ( phewoar phewoar)