Most baseball tour companies focus on major–league venues, but may arrange overseas trips if you ask.
Agencies that normally don’t handle baseball may help you with games tickets etc. if you book through them.
Do your homework. The Web is a priceless resource for checking on a business’ track record. Use it. Check forums on travel websites like Frommers, Lonely Planet and Trip Advisor, among others. Check the Better Business Bureau site, too. If they belong to professional associations, see if they really are a member in good standing.
It’s your money and your vacation. Due diligence, always.