Scott709938, I sent you a personal message. Vynl9 has recommended a great set of amps for you but you seem to be concerned with the ad.
You said "That link you posted, I'm sure it's a fantastic tube amp, but... it's USA only :( Canadians are cut out of the loop. I live on an island lol... getting to Washington state doesn't take too long, 2hr ferry ride, but it's a big state."
I also live in Canada and I have bought and sold 98% of my audio gear from the USA and have never ever had any problems buying and most if not all ads make reference saying USA only.
Don't worry about it, if you want the product just send off an email to the seller, there are options of payment PayPal, send a personal cheque, wire money, which ever method you choose and the seller excepts, there will be a % if you use PayPal and you need a account to do this. I personally courier over a cheque, using a Canadian cheque but making reference on it that it is in US Currency or wire money. One thing is to make sure the seller has good feedback and make sure you ask questions regarding physical condition, nicks, scratches etc., working condition. If it is tube related how many hours are on the actual tubes, do research prior to buying any piece, be educated so no surprises come up. There are scammers out there so be careful, remember you are buying on what they are saying so there must be some trust there. I have had mostly good luck buying but got scammed once badly and some other pieces not in the condition as posted so I make it very clear now.
I send off a email saying "I see you have (name the piece with correct model number) posted in 8/10 condition, I would like to confirm there are no nicks, scratches, repairs or worn marks on the piece and that you have all of the original packaging and manuals. I also ask are they the original owner and how long have you had it and have they ever had any issues with it.
I checked out this seller of these amps and he has actually answered most of those questions in his actual ad, just was not clear on and scratches, dings etc. so you would want to ask. He does have one negative and I looked at that, make sure you have gear insured for the cost this way if something happens you have something to go by to recoup. Once the seller has received your payment and it had cleared then he will ship and should email you over a tracking number that you can follow. Don't forget you will have to pay for Customs (duties and taxes) upon arrival which has nothing to do with the seller.
Regarding shipping, there are lots of options and it doesn't matter that you live on a Island as I'm sure product comes and goes there or you go to shore to pick-up. Fed-Ex or who ever else, just confirm shipping cost first because you will have to send this money off to the buyer also.
Hope this assist you, I'm sure I have opened to flood gates for you now with this info.
In closing I noticed you have zero feedback, member since June 2007 and not very active on Audiogon so this could have an effect of the sellers trust in you so make sure you mention that you have been a member and make reference to your threads and go from there. We all had to start the same way.
Good luck!