If bet365 can not pay you, just dedicate some effort and make a company offshore ONLY for them. But for tax optimalisation it is worth for other programmes as well. I think there is no need to clarify why Bet365 is no brainer.
Except that I suggest 5dimes, not only because they 100% respect deals, but because they are known to offer even smaller tennis events (****** limits like 100usd though).
Then another no brainer is Betfair, because the tennis market, especially live betting, is Betfair.
Well and another good shop is Pinnacle, because one year back they came with minor tennis as well and they are accepted almost worldwide (non US, ES, NL, TR, FR).
For the rest try Unibet, they are good auxiliary bookie and affiliate, and they operate in Italy and France, esp. if you have such traffic.
Tipico is good for German speaking countries, nothing specialfor tennis; same for Sportinteraction and Canada, their affiliate manager is top notch guy though.
Hodgeyboy@coral is very good guy as well, if they fix the live odds banners, it will be a very nice creative for tennis.
I suggest 1st look at your traffic and then choose the auxiliary bookies.
If you talk to God, you are praying; If God talks to you, you have schizophrenia.