Does a list or matrix exist anywhere that shows compability of Shimano road shifters, cassettes, and cranksets?

The reason I ask is that I have a Sora equipped Specialized road bike with the original drivetrain (except for a bottom bracket that I had to replace). The cassette and chain are worn out (after 20,000 miles over past 5 years), my LBS estimated about $200 to replace the cassette, chain, and 2 of the worn chain rings, which doesn't seem bad. But, I plan to keep this bike for a while and would love to upgrade the shifters to either 105 or newest Tiagra- whatever is needed to get away from the dreaded thumb shifter.

So I'd like to follow the LBS advice but also upgrade the shifters if it isn't cost prohibitive (since this is only a ~$900 bike to start with). I can't find anything that would answer this on the Shimano website (and would ask my LBS but am out of the country for several months, and would like to have a plan in place before I get back to the US).

Thanks.