DIY Cabinet - questions!

[ForHerDeadEyes]

I've decided to build my first cabinet, a 1x12.
I'm going by the measurements of a pro-made cabinet, in centimeters.
Height: 45,5
Width: 57
Depth: 29,5

I planned on using boards of spruce, 21x120mm:
http://i.imgur.com/QMpt72L.jpg

But maybe it's better if I get a "particleboard"(?), 22x600x1800mm:
http://i.imgur.com/15m2bZs.jpg
(The pictures are from the website of the company I'm buying from.)

The speaker I'm going with is: Celestion G12 K-100 8 Ohm

The cabinet would've been closed back, but seeing this video:
https://www.youtube.com/watch?v=tH1poQnuYng
I'm thinking of porting it.

I know there's a ton of mathematics and engineering involved, but I'd appreciate your input here. Any input at all!

 

[sprack]

Don't advise particle board. 19mm björk plywood would be best. I had difficulty in finding full response info for calculating a ported cab properly for all but hifi or PA speakers. The guitar speaker mfg's don't publish as much and you end up guessing.

 

[ForHerDeadEyes]

Don't advise particle board. 19mm björk plywood would be best. I had difficulty in finding full response info for calculating a ported cab properly for all but hifi or PA speakers. The guitar speaker mfg's don't publish as much and you end up guessing.

Yeah, seems particle board is off the table..
Plywood costs too much for my budget, I know it comes down to how good I want it to sound. I can get OSB (oriented strand board) for cheap, for 10€ I could make two cabinets, although it's only 11mm thick, but I will be reinforcing with with an inside frame of 45x45 solid wood..