I am aspha miner aswell. I havnt researched everything, but i like to find a ships weakness, and have other ships that counter that weakness. For instance; a starbase has doomsday hull, but accompanied by 1 or 2 dreadnaughts or juggernaughts will give it doomsday firepower.
M.flysh, m.clorite, g.lictor, stafez queen, m.epitodte. f.sword, m.calcite are all good ships for a modest income as they have less upkeep than pr, and are also quite good to have in your stacks.