I have used LCN for the last two years. They do a wide range of gels for every eventuality - a fibreglass gel, sculpting gels, self levelling,coloured etc. It is expensive but the results are great. what is more important is thier customer service and their training, both are first class. You feel like you are part of a big family rather than another customer. If you have any probs they wil help you until it is resolved.
The sculpture gels are hard to master, but their self levelling gels are soo easy to use the one component resin is good and if I need to I can do a full set in an hour - I prefer 90 mins so that the client doesn't feel rushed
Good luck with whatever you choose.