We used private DBA style Renaissance rules on a self-made campaign map. The King won most of the tactical battle but lost the war strategically by being outmaneuvered in holding areas. That was 20 years ago and matters have moved on. I would not recommend DBR or other variants as they do not seem to cope well with Pike & Shot armies. I do like Maximilian! but it does not cover ECW. The search for the ‘right’ rules continues; you might get some ideas here: http://fanaticus.boards.net/thread/1158/ecw-start
I shall be looking forward to reading more.