there are a few loop holes with bucket seats...
primarily, they MUST be ADR approved. there will be a Tag on the seats confirming this, or a certificate.
one of the rules in VIC states, you cannot alter the mounting point from the seat to the chassis.... so get around this by using Stock rails from your model, and modifying them to mount to your aftermarket seat.
most seats will come with generic mounting bars, use hi tensile bolts, washers, and nuts, and do things up TIGHT!
measure twice, drill once.
g/l.