I did some research with the part #'s I wrote down and found out some more info. I guess the two Dell sticks were continuity modules, or CRIMMs. RDRAM motherboards apparently require all the empty ram slots to be taken up by these CRIMMs in order for the board to function.
The other 2 Samsung sticks had part #'s on them so I was able to do a search and identify them as Samsung 800-45's, which is PC800 RAMBUS memory. Just gotta go find some sticks on ebay. I'll stay with PC800 just in case the motherboard can't handle higher than that.
Looking on ebay, it's surprising to see how expensive rambus memory is...the Buy It Now auctions are at $100 for 1gb...much higher than even newer DDR2 sticks.