I've been looking at good software for custom offline maps as well, but I get lost very quickly and figured I'd let my favorite cartographer wade through it.
I found something to use until SmokyStreams has a product: I was able to create several maps of the park from multiple tile sets using the FREE android app OruxMaps. There is a map creator built into the application that still has access to online tile sets that were removed from the Mobile Atlas Creator (MOBAC) that I used to make maps for AlpineQuest. This morning I grabbed offline maps from Google Earth, Google Hybrid, Google Maps, Google Terrain, Microsoft Earth, Microsoft Hybrid. I'll keep trying other map sources until the MicroSD card on the phone is full.
What looks promising for your use is the free desktop app that you can use to make calibrated maps, the page says you can use this to:
Create a map from scratch with a customized version of TB Atlas Creator (See the download section)
OruxMapsDesktop + image (the map) + coordinates of the four corners
OruxMapsDesktop + a calibrated map for OziExplorer. There are a lot of applications that allow you to create Ozi maps (see Links section)
See this page, http://oruxmaps.com/index_en.html
and also the links page for other tools: