While it is true that we have manuscripts that date to at least 100 years after the NT was written, it must be said that there is relatively little variance in these texts. Thus we can be assured that what we read in the New Testament, no matter what translation, is what God and the human authors intended to be read!
As for translations, you will get multiple answers to that. For Catholics, generally speaking, the RSV-Catholic Edition is probably the most accurate. It is not perfect however. (Some will argue for the Douay-Rheims, but it has its drawbacks as well. Plus it is a translation of a translation.) The NAB is less literal, but incorporates inclusive language in a very poor way. Although the NAB is not as literary as the RSV, it is still suitable for Bible Study. The New Jerusalem Bible is less literal than the RSV or NAB, but still can be used as a study Bible. The translation itself is dramatically different from the NAB or RSV, but this is primarily due to the desire, by the editors, to avoid a similarity with the language and style of the King James Bible. Also, I find the NJB uses inclusive language in a much better way than either the NAB or NRSV. Compare Galatians 4:1-11 in the NJB and NAB.
As for notes, the NAB clearly has the worst, however they are not as bad as some will say. There is the occasional note that makes you scratch your head, but overall they are generally informative. Currently Ignatius press is working on a study Bible for the RSV-CE, which will be excellent, but it won’t be ready in a single volume for some time. As for the New Jerusalem Bible, I find its notes to be the best. They are much more thorough and helpful than the NAB. Also, the notes about biblical verses regarding Our Lady are actually quite good!
Obviously more could be said about this issue!