You generally wont find a B20VTEC from the wreckers. A B20 block will set you back up to about $800 max and a vtec head, usually B16A about the same, you should be able to get them a lot cheaper if you buy off these forums though. wreckers dont like to split up engines so you would need to buy the 2 separate motors and pull them apart.

here are a couple of places that you could check for parts-
http://www.japaneseimportspares.com.au/home/
http://www.woodvilleautowreckers.com.au/index.html
http://www.japco.com.au/contact.html
http://www.startlocal.com.au/auto/wr...rs_396299.html
http://www.adelaidejap.com.au/adeljap/home

All of them can do Honda, but Woodville motor wreckers would be guaranteed to have the parts you need, pretty expensive though and bad customer service, but that is motor wreckers for you! I would keep an eye on the for sale section on here as well.

As for regency, I have never been but I believe they check everything from an ADR standpoint, ie- ride height, rim size, structural integrity etc. all of the things you mention are just maintenance issues, but why not just get them fixed before you go since you are gonna need to do them all at some point.