Lombardia is such a gorgous area! It's nice to drive from town to town- I found this area to be so quaint and tranquil. I especially like the lakes. I don't know in what area you are looking to stay, but this site has really neat apartments in milan that are quite modern and very central:

http://www.casamundo.co.uk/italy/lombardy/milan.htm

I do think though that a nicetrip though would be to stay near the lakes, as these areas are so idyllic. It's espcially nice to go in the summertime, although this is high season and they can be croweded with tourists. If you are thinking if staying by the lakes, this site has some apartments along the lakes:

http://www.selfcateringhols.com/region-97

And here's another site that has a variety of options:

http://www.holidaylettings.co.uk/lombardy/

Hope this helps!