Myst was the first instalment in the series, Riven, the second. As for Myst End of Ages, I bought when it came out and had so much difficulties playing the game, that I gave up after a month or so of trying to find a solution. I have a PowerPC iMac btw so not exactly your exact problem but fwiw I wouldn't give Ubisoft any money and would never mind the game. The part I got to play was a great disappointment story-wise and it was just a in-your-face look-at-all-the-3D-pizzaz-we-can-now-put-in-a-game exercise and the series had gradually lost its soul after Riven anyway, imo.
If you absolutely must buy this game, your best bet would be to take a look at the Ubisoft gamer forum. They should let you know about playing it on an Intel-based Mac. But a word of warning: help to Mac users is pretty iffy at best. For my problem I even went and posted in the Apple Discussions where other Mac users were having the same trouble I was: Ubisoft was pretty clueless when I posted there.
In case you're curious, the problem I had was that the game itself had very poor support for Macs using ATI video cards and you could only get to play it with all textures and effects at the lowest setting (my graphics card has 128 MB!). Ubisoft made it quite clear they would not release a patch for Macs (PowerPC back then), that the support had reached End of Life as they put it, all the while churning out patches for Windoze. It was quite obvious to me that Ubisoft couldn't care less about Mac users, the very same they had done in the past.
