IMO, get the largest apature your mate can, rather than go-to. Andrews Communications has the GSO (Guan Sheng Optical) 10" dobsonian for $750, and the 12" for $899. They are located in Sydney:
http://andrewscom.com.au/site-section-10.htm
I'd also suggest to let the girlfriend get the eyepieces herself. This way she can customise the scope to her liking.