Half-life is a great linear FPS with little story (how I remember it) and few "cutscenes" (pretty slow start) and it is marred by platforming and the ending.
Half-life 2 is a "rollercoaster" that is highly dependent on the physics "gimmicks" and driving sequences. It has a great ending and it is probably the best post-2000 PC single player FPS experience ever (along with Far Cry and Bioshock). I'm not sure if we'll ever see a single player campaign like that again (CoD doesn't count).
So if you hate challenging shooting and/or platforming skip Half-life but don't miss HL2 (the episodes are kind of forgettable).
If you need international layout get a 'Das'. It is in the expensive part of the middle range but it is built like a fort. I have the brown cherry version and I bottomed out a lot in the beginning with my stumpy finger coordination (maybe the blues are better) but I guess you get used to it, it gets pretty comfortable in the long run and it will last you many years. I also have a Steelseries 6v2 and the black keys are mostly only useful for platformers.
In the unlikely occasion that your mechanical keyboard might break you can just retire it as a pretty sturdy blunt weapon.