Can't decide which mobo :/

Hey all.
I finally found the Q9450 CPU at an affordable price and now I need to upgrade some hardware.
Here is what I have:

Intel E6600 CPU
Asus P5W DH Deluxe
ATi X1300XT 512Mb PCI-E
2x1Gb Transcend AXERam DDR2 PC6400
Akasa 500W PSU (won't change)

I know that Q9450 CPUs do not work well on my mobo, and this is my biggest problem.
There are too many options and I can't decide which mobo is better to get.
If I get a X48 or 790i mobo, with DDR3, I have to change memory too. Some people say it's worth changing from DDR2 to DDR3, others say it's not.
Then the only thing I would keep is my video card and PSU

Then I ask you: If I choose to keep DDR2, will I benefit all I can from the CPU?
I know the best to do is keep everything updated. And I think my actual setup is like that. So If I take one step ahead changing the CPU, the best would be to change everything. Or not?

Damn, it's hard to decide.
If I change everything, I'll be on a budget. But I can do it.

I don't need the fancy stuff like the wireless and the remote I have on my mobo.
Need at least 2 PCI slots. One for my Hauppauge card and one for my old Sound Blaster Live card, which I may leave if the onboard audio on the newer mobos is better.
Have 3 SATA HDs and one IDE DVD-RW. Won't buy any new drive soon, I think.
Don't need RAID.
And won't do any major overclock. Just what the stock cooler can manage.
Fancy stuff is not needed, but I want a mobo as good as the CPU.

ANY help is appreciated.

Thanx.

Upgrading mobo, cpu and video card and not upgrading memory seems a little controversial.
But indeed I was looking the video cards too. A frined had a 8600GT and I think it's more then good for me, as I'm not a gamer anymore.
What would be the ATi equivalent to the 8600GT?
Don't have any preference between Nvidia and ATi. Would get the best cost/value relation.

Asus Maximus Formula

Another thing. If I choose for one of those mobos, will I have to change my video card too?
Need to read a little about that PCI-E 2.0 thing. Since I don't play much games anymore I'm totally lost on the subject.

Just read an excellent review of the Maximus Formula and that's the mobo to get!
HD3850 and 9600GT are double the price, compared to HD3650. And maybe I don't need all that. Maybe.
Maybe it's better to save the video card money to buy another 2Gb memory kit.
Will bargain all I can

Can't find Gigabyte mobos easy here. Only the expensive ones, like X48-DQ6 and X48T-DQ6.
About the "waste of combination", it's what I wrote some posts before.
I know the right thing is to keep a balance. But everything is expensive here. Double the price.
I have a Transcend AXERam PC6400 kit. Could buy another one.
Or save the money and get a better video card.
And HD3680 is not a "office work" card. Far from it. For office work I could keep my X1300XT.
I'm not a gamer anymore. And I'm sure I won't play any heavy game in the next months.
HD3650 would be enough for me, but I don't mind getting the HD3850 if I can live with 2Gb.
It's one thing or the other, can't get both

Good luck.