grafting rootstock... cheap alternative ?
 

Hi. I am looking for cheaper alternatives for tomato grafting rootstocks.... I understand the modern and costly hybrids are the way to go, but for practicing the techniques ... is there also a good choice, widely available and less expensive ?

I'm in zone 5, Montreal

I already know of "petit moineau" and "Celebrity" being used as rootstocks sometimes

looking for more options please....

thank you for your help

stef