Single Entry Tourist Visa Application Help (Maybe 45 day??)

Hi All... Can anyone help? :-)

I have been trying to apply for Single Entry Tourist Visa on the Thai eVisa website (I am from England)

However when you get to the last page 'Supporting Documents' it has around 10 options. Most dont apply to single entry visa, but I cannot progress as all options are a MUST to add something?

I have double checked and I only need to confirm a couple of things with the documents so not sure how to proceed? Anyone have this problem?

Also wondering... Is it probably worth just going in on a 45day stamp, then going out the country for a few days or a week then coming back in on another 45 day?

Me and my family are in Thailand around 3 months.

Thanks in advance everyone.