It is perfectly ok to apply for visitor visa while ITA is issued and someone is in the process of submitting it. Some people go for a recce and get a job offer which kicks process fast.
For visit visa you will have to fullfil requirements of visitor visa which you can find from the nearest embassy/high commission. I personally do not see any problem with your visitor visa as long as you satisfy visa officer you have sufficient funds and what your intention is. It will be good idea to contact with few recruitment agencies and make appointment with them. This will help visa officer to make his mind positively.
Hope my thoughts help a little bit.