In reply to kingjam:
Three things that might be worth bearing in mind are:
1) low heels make a shoe more stable which means you are less likely to sprain an ankle. (Off-road you won't need as much cushioning as road shoes). For me, that rules out the Salomons I've seen.
2) Get shoes that drain well. Again, this rules out Salomons: you want shoes that are easily permeable low down, preferably where the movement of your foot will pump water out. Don't be taken in by the Gore-tex myth when it comes to footwear: most water will get in over the top at the ankle.
3) If you enjoy your trail run, you may well find that you want to start fell running, so get shoes that will allow you to expand your repertoire.
I really like Mizuno Wave Harriers, though for wet rock and grass, and mud they aren't as good as full on fell shoes.