If you're new to toys, diameter makes a huge difference.
The both the Platinum Silicone Super and the Scout are 1 5/8" in diameter, and for vaginal use anything larger than 1 1/2" (which would be 1 4/8") is generally considered to be on the big side. So, depending on whether you've already had a penis that wide inserted or not, you might find it uncomfortable.
The shapes of the two toys are nearly identical. The material listed is the highest grade (safety rating of 10) silicone for each. The Scout is by Tantus, which is well-known as a company that makes high-quality silicone toys, while the Platinum Silicone Super is by Doc Johnson, a company that is just starting to get into the market of high-grade silicone toys.
Frankly, you've picked two very nearly identical toys.