Thanks for all the replies and suggestions, the two brands/models seem to be very even.
QuiltnNan - the P stands for Perfection and it actually seems to be the same as the Q model and attachments. It seems to be the only Juki straight stitch machine avaliable internationally (or at least in New Zealand).
bigsister63 - Unfortunately I don't think Amazon ship sewing machines internationally and the voltage wouldn't allow it to work here without a transformer either, so I don't really have any other price options. The importer is located at basically the other end of the country but it does have a 2 year manufacturer's warranty. No, the knitting shop is actually just a knitting shop that also sells sewing machines but nothing else sewing or knitting related.
Prism99 - Thanks for the suggestion of Amazon reviews I will have to have a bit of a read. Think I'm starting to lean towards the Juki and definately am not keen on fussy tension.