Two 3 month tourist visa's in a year?

[Zzz]

Okay so i'd like to spend a total of 6 months in the USA.

I was planning on 2 months in Hawaii and 4 months on the mainland..

Now, what confuses me is the visa.

I know you can get 3month on entry.

To get the 6 month one; you have to apply once you're there..yes? And there is no guarantee that they will give you one.

That doesn't really help me, because if i only have 3 months, i don't want to 'waste' 2 months of it in Hawaii. And if i won't know until i'm there.............. you know? It's just not going to work. =/
For what i want to do/see - it's just not long enough.

So i was thinking of spending the 2 months in Hawaii, 1 month on the Mainland west coast then head onto Canada for 2-3 months, and then BACK to the USA for another 3 months.

That works for me as i'd love to go to Canada, and it would mean i could spend the summer in Canada with the slighly cooler temperature, rather than the 'hotter than the hinges of hell' temperatures in the South which is where i was going to spend my final couple of months.

So that would mean getting two 3 month visa's in one year.
Is this possible?
What are the chances of it being turned down?
Is it like 'suspicious' ?
Will i have to attend an interview?

Any other information i've missed off?

I'm a UK citizen if that makes a difference..

Thanks

[PraetorianXI]

Do you have a visitor visa (B-2) stamped in your passport? or you plan on using the visa waiver program.

Either way, how long they will let you in (even if they let you in). Is at the discretion of the POE officer and you being on "vacations" for 9 months does not show strong ties to your home country which makes it harder to obtain a 6 month entry to the US.

[Zzz]

I don't have anything stamped in my passport. I don't even think the passport i have now, is in date! Lol.

This trip isn't happening for a good couple of years.

And i'm actually travelling for 18 months around the world before the States.
I am going starting Uni when this trip is over, but i can't secure a place that far in advance to prove my ties..

Hmm..

Okay so it's unlikely i'll get the 6 month visa then.

Fair enough.

How about the two 3 month visa waiver's that i described above?
What's the likelihood of that happening?

[PraetorianXI]

If you obtain a visitor visa, for 6 months, for tourism purposes there should not be any problem (being an UK citizen helps, as you do not come from a third world country).

You will have to apply for one.

That is more likely than 2 separate 90 days entries (under visa waiver program) within 9 months.