FYI, it's against the rules to double post. Just edit your last post if you need to add extra information.
A PCI-E 2.0 card can work in a PCI-E 1.0 slot, it will just be slowed down by the reduced bandwidth. AFAIK, all motherboards since LGA 775 came out (Core 2 series) all have PCI-E 2.0 slots. You don't have to worry about this.
PCI cards cannot physically fit in a PCI-E slot, so they are incompatible. Typically motherboards will only have one or two PCI-E x16 slots, one or two PCI-E x1 slot, and around 2-4 PCI slots. Less depending on the size of the motherboard (e.g. M-ITX, ITX, M-ATX, ATX, E-ATX).
For the motherboard... my limited selection of Australian sites aren't working for me, so I just used the top one from google.
This motherboard is the cheapest on the site at $64. It uses a H61 chipset which I didn't know existed but, according to
Wiki, actually does. Either way, there are many more motherboards on that site that can be considered.
This motherboard is the cheapest with H67 (which'll have SATA 6Gbs instead of just 3Gbs), at $94. P67 is $138 and up for some reason, and Z68 is $177 and up. I've no idea how these prices stack to other Australian sites (considering that electronics in Australia are overpriced anyway) but at least it's been "located" for you.
EDIT: Since you posted (again) before I could... the
ASUS motherboard you picked has a GPU overclocking function and a surge protection feature, and the
AsRock motherboard you picked overcame the lack of USB3/SATA3 in the H61 chipset design by adding their own. Basically the AsRock motherboard has more features, but costs more. On the other hand, the ASUS motherboard has better software support (e.g. AI Suite II). My opinion is that they both suck since they're designed for energy saving environments and not for gaming, but you can't get a high quality motherboard on a low budget.