i've got a ECS l4s5mg. same board as the shuttle ms-51n.
quite a nice board
supports 533 bus, has built in video, ddr2700 , built in lan, sound, etc. $49 newegg refurb. great huh.
can do 4:3 and 5:3 , 3:4 , 4:5 mem ratios. itsgreat. and well SUPER CHEAP
i've heard good things about the ever cheap chaintech 7sid also, for socket a. who needs many slots anyways... with all the stuff built into boards now, you might only need 0 to 2 slots. right now , i'm using 0 on my board, until my gf2 gts comes. then it'll still only be 1 slot;