All I can give you is some names and sites. Gabriele Nebe co-owns the Lattices site with Sloane, http://www.math.rwth-aachen.de/~Gabriele.Nebe/  and http://www.math.rwth-aachen.de/~Gabriele.Nebe/LATTICES/  and has some work of her own on high-dimensional lattices. She gave a very positive review of a book by Jacques Martinet, *Perfect Lattices in Euclidean Spaces.* Finally, you might look through every publication by Daniel Allcock, he was the most helpful to me on my final covering radius question, http://www.ma.utexas.edu/users/allcock/