Your Strat will have standard 250K pots in all positions, and if that's a Mexican Strat I'm pretty sure they'll be good-quality US made parts.
500K pots would theoretically open out the sound and make it a bit brighter, but also possibly a little harsh/glassy. I wouldn't think there'd be any reason to change the 250Ks unless you're unhappy with the Irish Tours when you fit them.
And I'm sure you won't be unhappy with them. :D