GoHz is a manufacturers-based online shop in AC power supply industry to provide solutions for changing regular grid power frequency (50 Hz, 60 Hz), DC power source to adjustable frequency & voltage source. Solid state pure sine wave frequency converters, variable frequency drives, DC to AC power inverters etc. are for sale in affordable price on GoHz.com
Since most electrical power equipment is manufactured with a reasonable safety margin, you should be able to use a transformer manufactured for 50Hz in a 60Hz network, and even at 20% higher voltage, and correspondingly 20% higher throughput rating. It will be advisable to consult the vendor, and maybe modify cooling fans (if any) - perhaps just reduce the fan blades a little, as they will try to run nearly 20% faster, which could result in over 60% more power required for the same fan.