Hi Del: didn't realise you were in Australia, however, all is not lost. As Roy G suggests try Genes Reunited. I found a lot of information from there, and have met up with second cousins I didn't know existed.
FHL film - unfortunately the Family Search website is down at the moment, or I would have checked it out for you. Family Search is the wesbite for the Church of Jesus Christ of Latter Day Saints (Mormons). They have family history centres all over the world and there you can order and view films of parish records which they hold in their main library. Once the film has been ordered and received at the centre you will be able to make appointments to view the film and make your notes. The cost of hiring the film for 3 months is quite minimal - just over £3 here in the UK. The Family Search website has the library catalogue listed and you would be able to search to see if the parish records have been filmed, and they also have a list of their family history centres, but you will have to visit to order the films, you can't do it by phone or e-mail (at least you can't here).
Or perhaps if you Google you will find the Family History Society covering Brighton, and find their website - they may have transcribed the parish records for St Nicholas.
Hope this helps.
BumbleB
Family Search now up and running - they do have films of the St Nicholas, Brighton. As it appears to be the main parish church there are a large number of films, so you will have to be have a good idea of the period of time.