Go for Masters with Business/Economics/Marketing as Major and CS as Minor or vice versa. You do have nice percentage to get into Masters and with your experience and good SOP you will get SP without any issue.
Rest is your decision to which University/Program to get into.
Hi, If you need a partner to share room please state your profile. What's your destination, which school are you attending and where do you want to share the room blah blah blah. :D
What is POE stated by CIC?
To answer your question. If you don't have LOI - No problem i guess you have the TRV and UCI Number so when they enter your UCI into their immigration system they will get all the details required.