There aren't any documented issues with the P6T's and RAM. Buy good RAM and you won't have issues. If you do, the board needs to be RMA'd (happens with any brand). The P6T Deluxe is rock solid and one of the top overclocking boards. The V2 is just as good and a few bucks cheaper, the only difference being the lack of SAS controller. The EVGA boards are great as well, but may lack a bit of the stability at high overclocks (this is based on trusted hardware review sites, I've only overclocked with the P6T Deluxe so far). As far as graphics cards go, I would stick with EVGA on that front. I understand it's more convenient to have 1 company, but in my opinion, the best build would be Asus Mobo and EVGA GPU. All that aside, you'll be fine if you decide to go Asus/Asus or EVGA/EVGA, all are great solutions.
In regards to EVGA's warranty applying outside the states, here's the fine print:
# The EVGA limited lifetime warranty is only eligible for products purchased in North America, and Canada.
# The EVGA limited lifetime warranty is only eligible for part numbers ending in: -A1, -A2, -A3, -A4, -AR, -AX, -CR, -CX, -DX, -FR, -FX, -SG, -SX.
# EVGA does not ship replacements to PO Box addresses.
# EVGA will cover all return shipping back to our US and Canadian customers for the RMA replacement with free ground shipping through UPS in the United States and free FedEx Ground shipping to Canadian Customers.*
# Customers located at military addresses (APO, etc) addresses, or outside the United States or Canada, will be responsible for return shipping.*
*Shipments being sent outside of the United States are sent through FedEx as Standard shipping. All RMA replacements to countries outside the United States will state Warranty Replacement on the package to assist in avoiding any Brokerage Fees through customs. EVGA is NOT responsible for any fees charged by the destination countries government body or brokers due to brokerage fees.
I would contact EVGA to clarify, but my interpretation is that if you buy the card from an American retailer the warranty is valid, but you would have to pay international shipping if an RMA was needed.