Congratulations on your purchase. First of all I am not personally familiar with CCW yet but I am constantly reading peoples thoughts on it. Most people will probably advise against small of back carry. There are dangers of hurting your back if you fall on it and just not a fast draw. As far as tuckable holsters that are IWB many people recommend three holsters for the XD: Tucker's "The Answer", the CompTac C.T.A.C., and the Blade-Tech UCH. I just ordered the Blade-Tech but haven't received it yet to tell you anything about it. I'm sure some others will chime in with there thoughts. Also check out www.pistol-gear.com it is run by one of this sites sponsors and he is very helpful and informative when it comes to the XD.