In this sample sentence:
请你跟我跳个舞好吗?
Would you like to dance with me?

Which would be the right ge in this case
qing3 ni3 gen1 wo3 tiao4 ge4 wu3 hao3ma5
qing3 ni3 gen1 wo3 tiao4 ge5 wu3 hao3ma5


个 gè individual / this / that / size / classifier for people or objects in general 個

OR

gè variant of 個｜个 箇

Is this sentence more like, would you give this dance to me and thus the first one ge4?

Thanks,
Alex

Here 个 is used as a classifier for 舞, so it’s a neutral tone. Variants such as 跳只舞 and 跳支舞 are also frequently seen.

Also, I don't think you ever want to use 箇--it doesn't correspond to neutral or fourth tone, it's just an obscure variant. Unless I misunderstand. So you always use 个 (simplified) or 個 (traditional).