Suggestions?

Hello I just recently got a job for a local company. The website they are using now i think has joomla 1 and gallery 2, as of now i'm not even sure who their host is, so it is possible they have a different set up. What I was wondering is if anyone knew the best compatibility stages between the two softwares. Like for instance they were saying they were having problems with their current setup they were asking me what versions of the softwares were the best. If anyone knows this or has a perfect setup between the two and hasn't had any problems feedback would be great.

Thanks,

~Sanford