the MC2 is good but most likely won't work with GT4... I have one and use it on games from the PS1 and PS2... but it won't work for GT3... so I'd guess that it won't for GT4... you can always try it though... I got mine for $20 at Walmart.
as for the logitech wheel... it should work on any console. PAL or NTSC.... The support for games is on the game developers and not the wheel... so it's up for grabs on which games will work with it... I know it was made for GT3... but that doesn't even mean that GT4 will support it... and the MC2 and Logitech wheels both use analog brake, gas and streering....
Infact I know that the MC2 has Dual Shock mode (for games that don't support steering wheel), Digital mode (for the old PS1 games), and Steering Wheel (sony specific controller type), and all buttons can be remapped and steering can be calibrated on the wheel.
I've had my MC2 (Mad Catz) for about 4 or 5 years now... and have had very few games not work in one mode or another...
PS3 Slim 320GB
PS2 v11 exploit w/300GB Maxtor
PS2 v10 exploit w/80GB Samsung - Network Games
PS2 v10 exploit w/60GB Samsung - Network Games
PSP 1001 3.52M33 w/10GB total storage
NDS DSReal 4GB