What are the best visa options for a family planning to stay in Thailand for 7-8 weeks?

If you're planning leaving and re-entering Thailand you may be better with a multiple entry tourist visa

Get a 60 day single entry tourist visa from either the Thai Embassy or the the Thai consulate in your home country. Check out the requirements on your home country Thai Embassy or consulate websites. Often there are different requirements for the same visa required by differernt Thai consulates/embassies. It costs $60 for the SETV in Australia. As opposed to coming in visa exempt and getting 30 days on arrival, which you can extend at any immigration office in Thailand for a further 30 days, also giving you 60 days in Thailand at a cost of around 1900 baht and up to half a day waiting at immigration. Do the comparision with your home country consulate or embassy visa fee. Both of these options are simpler than a border bounce. Depending on where you are and how close you are to a border, the cost could be more or less than the two options I have described and could involve a whole day sitting in a mini van travelling to and from the border and at some borders now they require at least one night stay in the country you have crossed into. It is a good idea to have evidence of a booked and paid for onward journey out of Thailand either by air or bus. It is unlikely you will be asked by Thai immigration on arrival, but you could be. Less likely to be asked if you have a visa. More likely to be asked for proof of onward travel by the airline you travel into Thailand with.