Ahh, that old wive's tale about foreigners going thru the legal system here not getting a fair shake raises its head again!I asked an "experienced successful farang legal guy" here in Pattaya blah-blah-blah.. He also claimed they are the only legal firm who can win a case for a foreigner here in Thailand..
That's so often repeated and yet I've seen foreigners win case after case here. It is my experience that the legal system/courts here aren't really out to screw anyone over and try to dispense a judgement in line with what ever law you're arguing.
Now, the better you are equipped to navigate the thai court system (ie; speak, understand, read Thai) the better the odds are in your case. Still I've seen people who can't speak a word 'o thai come away with judgements against thaiz in cases. It just depends on who represents you.
I'd tell the O/P to take free consultations at all the top firms here and see which one appears dialed in to contract law where purchasing a business is concerned.
The reason you don't hear too many horror stories about ANY Thai law firm out on the inter-web is; given the broad interpretation of "libel law" in this country, even if what someone said was 100% true and factual, IF the business imagined their livelihood was impacted negatively by the story they could have a claim against the person who wrote it.