I would jump at the chance at a 301!! Its pretty much a FW on steroids and you have the benefit of it being a full sized portable that only weighs a tad more than the FW.
The 99 is a 3/4 machine so it is compact but heavy. It uses a class 66 bobbin and a lot of the parts from a 66 will interchange.
So if I only could get one of them it would be the 301A.
Billy