No shouldn't be any probs, plenty have done it before. even got a couple of trusted import dealers on here who sells imported models so take ssome of the hassle out for you.
Don't know of any disadvantages over reliability on gearboxes between manual and auto
seat is adjustable on UK models but not sure on JDM but imagine it would be
Insurance can be a bit more for JDM's. Have a search in JDM section or the insurance section and some answers will be there.
by the way and good luck on ya search