I saw this post yesterday.  Been-there, done-that a long time ago.  I personally have been using SoftPC on my Lisa's since 1994.   I even have had made lot of tweeks to make this work better.  
1. I use a version of SoftPC called "Entry Level SoftPC", this version is optimized for 68000 ( not 68020 +) based systems.  
2.  I made a special font called DOS13 that is a 13 point font to run full screen on a screen mod Lisa at full resolution.
3. I had James add a special option to the MacWorks+II Keypad control to add extra keys needed that the stock Lisa does not have.  This remaps the clear key on the num pad to be a needed key using SoftPC.
4.  Under MW+II with the 18Mhz XLerator this runs quite well, runs as fast as a real PC-AT if I remember correctly. 
I can provide more info if folks are interested.  
Rick