kyushu railway pass

need some clarification on the Kyushu Rail Pass before i purchase them.

1. as a foreigner can we purchase the rail pass 3days or 5days when we arrive in Fukuoko? will the price be the same?

2. is reservation for seats before departure required? i dont understand the train with reserved seats and non reserved seats in the website.

Obviously, the 5-day pass costs more than the 3-day one (otherwise, why have a 3-day pass at all?). All the prices are here:

http://www.jrkyushu.co.jp/english/railpass.html

In general, and especially on the Shinkansen, reservation is not required. Reservation is required on some special trains; iin doubt, check Hyperdia (if it displays the "Unreserved seat" option in the drop-down box, reservation is not required).

I brought and used the pass 2 years ago.
Yes you can buy it at Hakata Station.

Reservation is not compulsory, however if travelling on Shinkansen 800 series all seat the same and really comfortable. however on N700, reserve seating are layout 2-2 seating whereas unreserved are 2-3 seating.

You will rarely see train that are fully occupy part from 1 or 2 key trains.

Reserving train was free and guarantee a seating for you. Each carriages on long distant train are specifically assign as Reserve seating and non reserve seating. Its label in pictures and Japanese on the platform and train.

Thanks Jensen & Firas.

What I meant on the price was if buying it online is cheaper than getting it at hakata station.

I believe you're trying to ask if the rail pass costs the same bought outside of Japan as within it. The answer is yes.
As for reserving a seat, it is not really needed for most, unless it's busy and you want a seat on one particular side or window/aisle etc.
In Fukuoka City you can buy it at Hakata Stn., Fukuoka airport, and the Hakata Port Beetle Counter. You don't have to start using it at the moment of purchase - you can designate which day you want to start using it. This helps a lot if you want to start from a smaller train station. It'd be smart to see Fukuoka first and then start using the pass. There are many good areas to see. There are many parks and places to walk around. You might look at:

http://www.tinyurl.com/see-fukuoka

as well as look through:
https://www.youtube.com/playlist?list=PL7LcPcmoSg-j4RLa6iC7ayvBAbOn8-0...
Don't miss Nanzoin - one of the best temples in the country...and almost unknown to the outside world:
https://www.youtube.com/watch?v=lT4VQFmHFyM
Nagasaki, Beppu, and Kumamoto are also worth time to explore in northern Kyushu.
https://www.youtube.com/playlist?list=PL7LcPcmoSg-gbw2yXNLK92siHyNqSNx...
https://www.youtube.com/playlist?list=PL7LcPcmoSg-hOggZamc2lUNTr46ApKX...
https://www.youtube.com/watch?v=K9xyXmU8U1g
Kyushu is one of the underexplored jewels of Japan - I'm sure you'll love it.

Thanks Ken for the useful info.

I have 12 days in Kyushu excluding travelling days and my base will be in fukuoka.