I got the exact same one a while ago but its been a total nightmare to get it running right. Jet size could be anything from 88-110 you just need to buy loads of jets and plugs and try them out doing plug chops till you get it perfect.
There is no standard jet for open filters, its all trial and error.
Unless you spend a lot or go for a bigger kit then your Agility is never going to go much over 43-45mph on flats. Even with a BBK you wont get much more top speed. If you need to go faster than 42- 50mph then get a bigger scooter.