#1
Ok so I wanna make the little gem amp and I need to know which of these speakers will be the best...I dont have a lot of info on them cause they are cheap old ones i found in the attic. I know these arent the best but im doing it for the experience and not for the actual amp.

Choice 1) Sanyo s12J49A which i got out of a old broken keyborad( but the speakers were fine) its 4 omega and 3 watts

Choice 2)Brand and model unknown...8 omega and 5 W

Choice 3) has a radio shack symbol and is 8 omega and 3 W

Like i said though im just doin this for experiance...eventually ill make a good amp but this is my first.
#2
Any of them will match I would guess... If the amp you're building is designed for 4ohms, then it will be loudest with the first choice.

And it's ohm(s), not omega.