Depending on what safety system you use will depend on which bolt is best suited to your needs, tang safety will use the the half cock type or if you choose the other the safety is already there, neither is wrong for what you want.
Tony looks like he may have stopped trading, i found this on the net.

http://abncheck.com.au/abn/19746482006

For your screws Alan Hibbs at Kingaroy firearms would have what you need.

HTH
Pete