AirProxy claims to provide a premium and high quality service. They say that "while most providers get their proxies through peer-to-peer networks, AirProxy does something different – it makes use of a dedicated sim card for each subscription."
AirProxy is not unique in this claim. The Social Proxy does something similar but technically smarter, with virtual SIMs.
AirProxy is an Italian based company and their responsiveness is very quick and very good.
Pricing starts at £80/month
For ease of comparison, we have provided prices in £ / month, though the vendors may invoice in Euros or Dollars.