Another take:
Driver distance is important, but I guarantee you will be hitting irons or wedges on EVERY HOLE. The "better" (not necessarily longer, but higher trajectory/more spin/slower meter) irons and wedges you get will leave better approach distances and chances at up-and-downs from missed greens.
At L39 you are going to Level up so quickly in the next few months that many different options will reveal themselves before you know it. Be patient and learn all the courses, learn the different types of shots around the greens to get up-and-down, etc...
If I were you I would hold off on irons until L59 Pings. You could go for the L38/39 TM 54*/58*/64* wedges now and they will last you quite a while and gap decently with the L59 Ping irons.
**Edit** If you are not opposed to spending a little cash, definitely Google search "WGT Steam Bundles". At your level/tier, a small cash outlay would get you clubs that can last you well into the later stages of the game. For every bundle they have you get almost as many credits as they cost (so a $20 bundle gets you some nice clubs AND $20 worth of credits that can be spent on balls, other clubs, so forth). If I was starting over I would buy these bundles without a doubt.