First of all, I feel that it is a weak argument to claim that direct revelation plus Scripture was necessary SOLELY because the canon was incomplete, since even a completed canon would give no military guidance to a commander today, in the sense in which David was extra-Scripturally guided. Could a modern general look at the Bible and deduce from it what military stratagem to employ against his foes e.g. a head-on assault or a flanking manouevre? No! So what bearing did an incomplete canon have on God's special guidance of David in that battle? Surely the answer is none whatsoever. Therefore it is a bogus argument to say that direct revelation is no longer necessary for every situation because we have a completed Bible. It would be better to link cessationism with the close of the foundational period of prophets and apostles than to base it on the weak argument I have just (I hope) proven amiss.
Secondly, Wes - I think you misunderstood me somewhat. I am not doubting the completion of the canon of Scripture; actually, I wholly accept its completion. And yes, if David's example was recorded in Scripture then it goes without saying that it should have been recorded. What I am trying to do is determine whether or not there are still instances of genuine special revelation from God in matters unrelated to practical godliness or salvation, i.e., as was the case with David's military guidance.
Through a bizarre succession of events, I have felt utterly convinced before God that a certain outcome to a friendship with a girl was assured; however, after an innumerable host of susbequent "false dawns", no tangible progress has yet occurred. Doubting the erstwhile assurance, I began a friendship with someone else and it is coming close to a time when an irreversible decision must be made. Sadly, I have felt now, more than ever, when praying to God, that the first girl was certainly promised... This places me in a serious dilemma and has caused me to completely reassess my long-held view that cessationism was 100% correct.
To close, I appreciate all your replies and Pilgrim, that was very helpful re Peter.