It’s risky, as you will no doubt appreciate, to advise a person one has never met regarding such a practice. In principle, yes: struggling against one’s desire for sleep—refusing to be controlled by the appetitive part of the soul, requiring instead that it submit to the rational part and, in turn, to the spiritual intellect—can be a useful exercise, and a good preparation for receiving the Mysteries.
But in fact the usefulness, and appropriateness, of such a practice depends on the motives, capacities, and understanding of the person in question. Pushing against one’s physical limits, or apparent limits, could harm the body and, much worse, could serve to inflate the ego of someone who was attempting to storm Heaven, as it were, by a show of power or prowess.
As for non-Orthodox readings (whether Sufi or otherwise), needless to say I see no problem with those, provided they assist you in the acquisition and development of the virtues: humility, charity, and veracity, above all. Do these texts help one to see himself more clearly and honestly? Do they empty us and open up a space within where God can act? If so, then yes: they are perfectly acceptable for the purpose you, as an Orthodox Christian, have in mind.