You should be absolutely fine. Unless there is a mistake in how games saves are handled or some bug in the game that prevents transfers, (which i truely would not be surprised at).
My original fatty PS3, high def TV, etc; was stolen in a burglry so i got a new slim 250 GB last September. I could'nt afford to buy an expensive high def TV at the same time so i had to wait until june this year and got myself a 24" 1080p BenQ monitor. I was looking forward to playing in high def again but when i hooked up the PS3... nothing. I changed the HDMI cable but still nothing. Turned out the PS3 i bought had a faulty HDMI port. Took it back for a replacement, there is a whole other nightmare story regarding that but i won't go into it here, got the replacement home and found the disc loader was faulty. It would take 3-4 tries to get a disc in or out. Got another replacement, a 320 GB slim with Killzone 3, and thankfully its been fine.
My point is that i was really worried about losing all my saves, that transfering them would'nt work. I had heard all sorts of horror stories about people losing everything. In the end i had to transfer all my data (saves, music, etc;) 3 times: once from my back ups to the new 250 slim, once to the first replacement and once to the second replacement and it went fine every time.
The only problem i had was losing my Assassin's Creed 2 saves as they were copy protected. I was a bit angry as i was 95% done with it but i love that game so it was no hardship to play it all again.
Again, unless there is a problem specific to this game of which i am unaware you should be fine. Just create the same user profile and link it to the same PSN Account, make that one the Master Account, and it should work no probs.
