If using -R TY then you will have no choice but to burn them at 4X as this is the maximum speed your burner will support. +R Taiyo Yuden may work well depending on your PS2 version. -R media may be more compatable with consoles overall, but it's what works with YOUR PS2 that's important. My PSTwo isn't fussy either way, + or -, for movies or games, I just chose TYG02 because my drives burn it well and it was cheeper than YUDEN000 T02.
If I were you I would buy 50 TY +R and 50 TY -R to see which work best for you. In all probability both discs will work well! The advantage of the +R is your burner supports them at full speed.
Check for a firmware update to your burner on the I/O magic site and search this forum regarding bitsetting +R discs and you should be set.
I used a couple of different media before TY, and experienced the freezing you described, spacifically on Need For Speed Most Wanted. This game loads the track and scenery on the fly, and with the first back up burned on Ritek media would pause for 10-15 seconds to load half way through a race. The TY copy functions just like the original.
Edit: All my backups are burned at 8X and sometimes over speed to 12X so slower burning is not necessary.