D300 for sure.
since you are using a 350, I'm going to assume you aren't pushing out 800+hp...
The D300 is easily adaptable to the 350, is small and compact, light (relative), strong, has good aftermarket support, and is affordable and readily available. Its easier to pack under a rig than a 205.
you can find them in decent shape for $200. find a stock circular pattern adapter from a 700r4 for like $40 and a $125 spud shaft from AA, and the D300 mates up to the 350 easily. output shafts are weak but have been known to hold up fairly well, it really depends on what power and tires you are running, etc. 32 spline upgrades are easy to install and affordable.
resale on a d300 is better, IMO and even better if its been upgraded and in decent shape