Need to run a hardware test on MBP4,1, 17" OS 10.5.8 w/out disc?

I have a macbook pro with the following specs:

- 17inch macbook pro 4,1, 2. 5 GHz

- non-unibody (released sometime in 2008)

- OS 10.5.8

My battery recently expanded and 'exploded', so i bought a new one (from macsales.com) and replaced it. battery works fine.

I also upgraded my RAM: from 2GB to 6GB (1 x 2GB, 1 x 4GB).

I have two issues now:

1) I have a birdlike chirping sound that occurs randomly and not often. I had similar sounds prior to my battery expanding and going bust. However, now that I've bought a new battery, I have a concern that it might be something else in the hardware.

2) I would like to upgrade my OS to mavericks; but first, I understand that i have to upgrade to Snow Leopard (10.6) before upgrading to anything.

I would like to know the following:

a) I would like to run a hardware test to diagnose it and find out what the sounds are from and also a general check up before i actually upgrade OS.

However, I don't have my installation discs because I moved country and it was a long time ago.

How can i run a hardware test and check my laptop without a disc?

b) since i'm not in the US, how can i buy the Snow Leopard? is there an option for buying when outside of the US? I can't seem to find it.

thanx for your help