What memory and m/b best serve e8400 cpu?

After reading several forums Ive decided to go with a P35 over the X38.However im torn over the P5K-E/WIFI-AP and the Gigabyte GA-P35-DS4/rev2.1 at clubIT(newegg has rev2.0)Im not sure of the difference though.Or even the new EP35-DS3P. And what about memory.I keep hearing about deviders and cpu frequency.I was going to go with ocz reaper ddr2-1066 or even 1150.I dont mind spending 100+ for good ram.And I like oczs customer support as you can always talk to a real person.They suggested that ram to me the other day.Im probably going to get a EVGA 8800gts.(512-P3-N841 A3)and step up to 9800 in 90 days if they come out soon enough.Or if the asus TOP version becomes available Ill go with it.Sorry I got off topic.Whats the deal with the memory?Is it really important to sink cpu & mem these days?Wouldnt 1066 be an advatage in performance? One last thing! BIOS. Idont have a usb flash drive and im not going to buy a celeron --so there.I do have a WD usb mass storage device though.If I have to flash will that work? Im upgrading from a A8V FX57 agp system so I have most of everything I need.Sata will be a pain with xp though.Itried to do the floppy F6 thing last new xp install and it didnt work.Any way which board and mem is good.I have a $900.budget.And thanks you guys for any advise.Ill be ordering in two weeks.

you will need another CPU that works to flash the bios, or the machine wont post with the E8400 and therefore can't get into bios to update it.
You can sometimes have the retailer update it for you for $10 or so before shipping.

Memory: Crucial Ballistix DDR2-800.

not all retailers will be shipping a 09XX bios with asus motherboards yet, but you can always ask them before you buy. Good to know they're keeping them up to date.