Hi
Answer to 1: Depends on how much experience u have with
Java. I have more than 4 years of Exp and I spent an hour a day for 1 month. If u feel confident u can take with 2 weeks of prep as well
Answer to 2: I think lot of companies have not yet moved to JDK 1.4. But if u say that u r certified in JDK1.4 people will feel more confident about ur abilities.
I hope I was able to answer ur questions
SCEA, SCBCD, SCJP1.4, OOAD-UML, OCP 9i