After a degree of pondering about how to go about getting the harder visas in comparison to the Mongolian visa, we decided to try using an agency. How impressive was the service we received! We completed the application form and paid online last Saturday week for the Kazakhstan visas. Sent off the passports to the agency on Monday, and we had them delivered back to us (with the visas) yesterday, a week after we signed up online. The service also allowed us to track the progress of the visa application online.
If anyone is interested in using the visa service we used, it was through a company called Real Russia. You can reach them at http://www.realrussia.co.uk.
The Russian visas are next in line!