to begin with I'd suggest a 16 inch... one that fits comfortably under your arm..... I used to play a 16 .. now I play a 14 inch and it is lovely...the advantage with a tunable is that if the skin is the wrong tension you can "fix" it instantly.... instead of the old water or heat that you need to do with non-tuneables....
some tunables need a screwdriver or allan key to adjust the tension, the Eamonn Maguire ones I mentioned earlier have "sliding wedges" built into the inside of the rim which work very well....
and he (and I'm sure the other makers) deliver anywhere...
slainte
alison