I would personally HouseRule that the Beguiler's Surprise Casting mechanic counts as equivalent to Sneak Attack (after all it is a Sneak Spell Attack for all intents). Then the Beguiler needs only get Mage Hand added to spell list either by Feat (which I have seen), by Advanced Learning, or possibly as a houserule add on - which is another possibility that I might strongly advocate as being appropriate to the Beguiler's theme (sneaky mage type), even if it does not fit exactly with the typical spell schools (but after all there are other exceptions).
Either way, a Beguiler could basically become Arcane Trickster with single class advancement in my book, which is appropriate to the theme of both the base class and the PRC IMO. Heck, if the arcane trickster was written now-a-days, instead of early in the history of 3e, then the prc would probably have provisions to include Beguilers.