We put a Regency gas stove in my parents' basement about 10 years ago. Part of the reason was to get some hassle-free heat even during a power outage, but it made the basement much more cosy and took it from "never used" to "frequently used". The flames look great and the stove has been as hassle-free as you would expect considering it has almost no moving parts
If you go with a gas stove make sure you get one with a millivolt thermostat (no AC needed) so you get some backup heat in a power failure. If your gas boiler runs without AC then doesn't matter so much.
That said, rather than a second radiator have you looked into a larger radiator ? One thing I saw a lot of in Germany was very attractive floor-to-ceiling radiators which put out a lot of heat. You might need a fan of some sort to move the air around but that would have to be cheaper than an installed gas stove.
Here's the one we put in (pedestal, gold door). The Jotul would be fine too.
http://www.regency-fire.com/Gas/Stoves/Classic/
