If i take the SCJP 1.4, and then about a month later take the SCJP 1.5 upgrade exam, would it be equivilent to just taking the 1.5 exam?
No. You would be certified as a programmer for Java 1.4 and Java 5.0. You would get two certification kits.
Also, for the upgrade exam (1.5) would i get the same certificate as if i were to take the full exam, or would it specify that is is only an upgrade?
I took the Java 1.4 upgrade exam, and in my certificate it doesn't say that it's an upgrade. I guess it will be the same with the Java 5.0 upgrade exam.
Yet, in your place, I would only take one exam. I don't see much point on spending more money. If you're planning on taking the developer certifications, it doesn't matter what version of the programmer exam you take. If you feel confidente on the material on Java 5.0, take that exam. Otherwise, use all the great and plenty material available for the Java 1.4 exam, and just take that one. That's my humble opinion.