is this a good turbo choice?

Diesel Turbo on a Gas motor has been done many times, successfully. As for the 2 different seals available, there is a carbon seal and a dynamic seal. Carbons are old school and cant be used with a draw through because of the vacuum involved, Possibly what was referred to. Another difference is Diesel turbos may not have an integral waste gate, but some do. Also diesel turbos usually have a larger exhaust side than a comparable gas model. They are also rated lower in diesel apps, ie, same 600 hp diesel turbo is about a 1000 hp gas turbo. So, as to your question, yes they can be used, its just sizing them that can be a challenge.