Much would depend on your level of experience with tortoises, the thickness of your wallet, and where you reside. Both are very hardy species when the husbandry is correct. Spiders are cheaper, smaller, have a more varied diet, require less space, and need typical forest tort (low light, high humidity, moderate temps) husbandry. The rich mans sulcatta (otherwise known as the Rad) has husbandry virtually the same as a Leopard (lots of space, hot, dry, and sunny) and will cost you at minimum 4 - 10x's the cost of a Spider and you need a CBW permit to own one, unless you live in the state they originate.
Unless you have a good number of years keeping torts I'd suggest a Spider for the reasons above. On the other hand Rad's are a very personable tort much like sulcatta's.
Good luck with your choice.