Mixed analog-digital power supply
Consider a pre-assembled multiple output DC-DC converter module.  I'm guessing you'd be looking for one that outputs +/-15V from 9-18V in?  You can probably even find one that has a third output with 3.3V.  They're usually not overly cheap, but they do simplify the design process, they at least make claims to meet a particular noise spec, and you can choose one that you're able to hand solder easily - either through-hole or leaded SMT.  They're readily available from the big vendors (Digikey claim over 200,000 DC-DC converter modules on their books).

For example, the LT3467 for the +/-15V part, and an LTC1174-3.3 for 3.3V can be used (or LTC1164HV-3.3 for a little bit more flexibility in input voltage), according to the schematics suggested in their datasheets.