Choose Samsung DDR TCCC or UCCC?

[Duplex]

Hi! I´m trying to decide between theese 512MB pc3200 DDR SAMSUNG modules:
all are (66pin TSOPII)

K4H510838C-UCCC -.??M368L6523CUS-CCC....C-die 512Mb single sided

K4H560838D-TCCC -...M368L6423DTM-CCC00..D-die 256Mb double sided
K4H560838E-TCCC -.?.M368L6423ETM..............E-die 256Mb double sided
K4H560838F-TCCC -....M368L6423FTN-CCC......F-die 256Mb double sided

(the dots are only for layoutpurpose)

Which is the better one? I havn´t found any good statistics or info yet.
UCCC seems to be a newer one and some says itll do 240mhz others 260-280mhz,
don´t know what to belive.

[I´m building a system with DFI ultra-D and AMD64 3000+]

Please help me!!! TCCD is to expensive for this computers budget.