Hi, you will be fine with any good quality transformer that exceeds the wattage of the appliance. You are unlike to have any issue due to frequency - in the unlikely event that you do, it will be a 20% speed reduction, not a fire or anything drastic.
I have bought all my 240-110v transformers from a local Auckland manufacturer http://www.tsltransformers.co.nz/ (incidentally, they can do them the other way to run kiwi applicances in N.A.)
Some one mentioned having problems with their appliances burning out $80 transformers - at that price it is likely that is wasn't a true transformer but a step down device using FETS or transistors (or worse resistors)- these are not as rugged as a proper transformer and a lot are poorly designed, hence they are unreliable. A dead giveaway is the weight - a 2,000 watt transformer will tip the scales upwards of 5KG. The none-transformers will tend to be 1/2, 1/4 or 1/8th of the weight. There are heaps of these things on aliexpress and ebay, but friends don't let friends buy them.
Others have mentioned that you may see a 20% speed reduction due to the frequency - this is true in devices that have synchronous motors - I suspect you will not have a speed reduction as an 1800 watt synchronous motor is too big and heavy to fit in a kitchen blender (think of a lath compressor or drill press motor) - it is more likely that the blender will have a universal motor (same as a vacuum cleaner) - these are not frequency sensitive and run on DC (eg rectified AC) in some applications.