It looks like Mark has the ULN2803's if you need them
http://www.pinballspareparts.com.au/index.php?search%5Bterms%5D=ULN2803&search%5Bmode%5D=any

I think RTBB must be sold out for time being.

The LM339's are available from Jaycar if you need some too
http://www.jaycar.com.au/productView.asp?ID=ZL3339&keywords=LM339&form=KEYWORD

PCB repairs are not difficult, but if you havn't done one before (ie desoldering IC's) you need to take care as to not damage the board which can end up being $$...

If you're going to have a go yourself too - I would strongly urge to ALWAYS socket rather than solder the IC directly onto the board too.  Lately I've been leaning towards the strip sockets more but a standard socket will suffice.