1) A guide mode is a feature that is "nice to have" at most, with a bit of basic knowledge (which you mention to be willing to acquire) it becomes redundant.
2) Have a look at the reputable shops once you have settled for a certain model. Alan Photo is listed there but based on some recent feedback it's not a shop you should consider.
2) Have a look at the reputable shops once you have settled for a certain model. Alan Photo is listed there but based on some recent feedback it's not a shop you should consider.