need a little help please

this is a brick outhouse that i've got and will be using to house a couple of motorbikes



obviously the single door is not really convenient for getting 2 bikes through, so i will be knocking a hole in this end wall and installing a pair of 6' wide french doors



what i want to do is use the bricks from the french door hole to brick up the existing single doorway, but how do i get the bricks out in one piece and get the mortar off to be able to use them again?

i was thinking of slicing the opening in the end wall with a 14" diamond disc cutter and using several large but manageable chunks of still together bricks so that the amount of bricklaying and mortaring would be less. is that a good idea? obviously i'd be removing the half bricks at the side of the doorway at the moment and tieing in the chunks properly.

the wall is just a single skin of bricks.

alternatively, if it's too much of a ball ache to reclaim the bricks, is it cheap and possible to buy that amount of matching bricks, or will they look too different due to weathering over 40 years?