DNA software for Windows

[William A. Dunn, Jr.]

I have been looking for a software package that does simple DNA manipulations
and vector drawings.  This software need not be freeware but more importantly
functional.  I need to identify those restriction enzymes and their sites of digest
that clip a DNA segments only once or twice.  Homology comparisons and sequence analyses
(antigenicity, amphipathy, hydropathy, etc ....) would also be helpful.  
Genepro is not in Windows format and I found it to be cumbersome.  Your comments
would be most helpful.  

Bill Dunn