I don't see the advantage to building the Samari, the Toy will be bullitproof with a lot less work. The width with be similar since you are planning to use Toy axles; however, the wheelbase on the toy will likely be longer (i.e better). Climbing is very difficult in short wheelbase rigs, I guess the flip side is potentially more excitement.
Consider this, you make a trip to Mecca...um Moab...and you roll up to Dump Bump with the crowd gathering. I would rather be in the longer wheelbase Toy so I could go right up. My truck is an extended cab long bed (wheelbase around 111 in) and it climbs much better than my friends Blazer (about 106 in). Wheelbase isn't the only difference between the trucks, but within reason longer is better.