Operating costs wise we'd need to know what your gas & electric rates are.
"Up north" means different things, and has different implications depending on if you lived in Los Angeles CA vs. Denver, CO vs. Whitehorse Yukon, eh? What is the freeze potential?
Atmospheric drafted gas fired tanks work fine in basements, in 1-3 story homes. There are no vertical length limits (some horizontal limits, an horizontal needs a minimum slope) but the diameter needed is a function of both the burner size and total effective length (including factors for any ells & tees). Vents that are oversized for the BTU-output of the burner leads to condensation in flue and potential backdrafting.
There is no particular efficiency advantage to elevating the tank off the slab unless the tank has no insulation on the bottom, but being elevated keeps lowers the flood-damage risk. In a less-insulated electric tank putting 1" of extruded polystyrene (XPS- be it pink, blue, green, gray, whatever...) under it and giving it a retrofit wrap lowers the standby loss slightly, but most are pretty good these days, and if it's off most of the time it won't be economic.
Water softeners eat the sacrificial anodes, but keeps the heater from liming up from hard water. It's hard to say what your replacement schedule on the anodes needs to be, but draining it isn't called for. (Draining it may be called for in a high freeze-risk situation though.)