Hey brother. A few kind words if advice. The odds of a tourist visa for a Russian or Ukrainian unless they are STUPID rich are soook slim right now. Just use Google and you will see the odds are the same in western countries . Small odds of a tourist visa if she is not really really established in Russia. Immigration will see her as a GF anyway and you are right to do the invitation option for 2 reasons. 1. NO WAY DO YOU SEND A LARGE SUM OF CASH! Your instinct is right on! The official will not read the details just the pre meeting in Russia and post plans. 2 AGAIN...NO WAY DO YOU SEND CASH! Any agency will tell you not to send large sums of $$. If she insists...use good common sense. Offer to pay with your own Credit card this way...no cssh issues and if fhe visa is not approved. .you may have some refund and it wilk stay in your control. Sorry... $$ is an issue of intense scrutiny and opinion. I personally know alot of immigration policy having been all over and lived in the UK too. If there js a 3rd point? DONT SEND CASH