Your greatest issue is drainage and adding a drain pipe which will connect to your existing plumbing. This costs thousands to install, added to the shower installation which can be less than a thousand if selecting a economy pre-built shower. You will be doing good to get a shower put in for less than $5000.
Buy a cash house, live in it while doing repairs. Either flip it or upgrade it at the same time your working on what wetdawgs is suggesting. By the time you have your credit restored you will also have equity in a cheap property to leverage buy selling, leasing, or mortgage.
try their county website http://www.bouldercounty.org/