Hey Paul. I use "The Analytical Hebrew and Chaldee Lexicon" by Benjamin Davidson (ISBN-10: 0913573035
ISBN-13: 978-0913573037 ) by Hendrickson Pub.
Everyone seems to like the BDB, but all the ones I see are designed for mainstream use. It focuses on the Strong's number system for instance. Bothersome if one at least knows the Hebrew alphabet. I normally do not buy books published in the USA, however Davidson's Lexicon is an exception. It is unique in that is has an excellent system of shoresh; the 3 letter Hebrew root words. Necessary for etymology. I found some srange root words that have certainly deepend my understanding(or left me dumbfounded and confused :^) )
As for your question on the Hebrew word for nakedness "eirom". I actually have it's root meaning: cunning, subtle, crafty. Now I find this very significant, in that in the same passage the serpant is also described as this, being refered to as "aroom", crafty. The Hebrew scriptures often have common themes like this in it's text. Also, each Hebrew root has at least three different, often conflicting meanings. What the theological meaning behind this passage is however, is up for interpretation....