well, it probably is a pentium then. as i say, i think red hat 7.* supports 486s, and definitely mandrake 8.2 and mandrake 9.0 both work on a pentium, and to be honest, functionally there's little difference between mandrake and red hat. If i were you i'd put mandrake on the older one and red hat on your newer one when you get it.
Be prepared to put a bit of elbow work in though as some laptops are full up of weird buggy hardware (believe me i know!) and some older versions of linux don't support the hardware. As i say though, if you have a pentium, you shouldn't have a problem running even the spankingest newest versions of linux on it, although it might be a bit slow.
by the way, why do you prefix your posts with 'girl needs advice'? (excluding the obvious!)