Gas dryers are very safe as it comes down to having it professional installed.
Since you are obtaining a new dryer, the individual that deliveries it will install it properly and to the requirements of local code. The largest concern is assuring that the hot air piping is connected with a metal style, thin-wall pipe. Once again, your installer will assure that is done correctly. Having the hot air piping cleaned at least once a year for heavy use, every couple of years for lighter use.
Do not waste your money on top of the line washer and/or dryers as they are all gone to onboard computers and 'need' to have separate electric sources all the way back to your main power panel.
