While dreaming of the coming of the ilClan, I did up a cheesy, Warwolf-ish...
Did you mean Wulfen-ish? Cause the designs you're doing are in the light 'Mech range, not the heavy.
Excel, unfortunately. No good purpose-made options. Lack of TRO format output keeps me from posting on the design boards.
Solaris Skunk Werks should be able to handle all of this. I can build the Skinwalker in it. You just have to set the rules to Experimental, the era to Dark Ages, and the tech base to Mixed.