i have an Onda D8P (i assume you mean onda not oanda but perhaps im mistaken.) its an 8 slot with 2.5 spacing between slots so 2 slot gpus still have breathing room.  its run flawlessly for years and has had fpgas as well as gpus in it. that model has a socket for the cpu and one sodimm slot as well as a msata ssd socket so is very self contained and neat as far as wires etc.

dunno if you can get them now. but it was a game changer from my riser rigs. what a mess when changing things around, cleaning gpus etc. riserless boards for the win.