I have a portable airconditioner that draws so much power that all my electricity goes out....the one for the window(got one too)is no option coz I would never be able to let my room air out and with too large tank humidity is a big factor..coz I would close off my window ..and again I would need to babysit from day to day..how about leaving for a weekend ..still no option..my tanks drive me crazy in the summer lol..i am really worried sbout a true heat wave someday in the 90..s
A chiller really does take the worry out of a hot summer and you can't go wrong which ever one you pick, the 1/3 hp or the 1/4hp for the big tank.
If it was me I would get the bigger one, just to be on the safe side. You have literally thousands invested in your tank and need to protect it. As long as I'm spending your money,,,,,,,,,,,,,,,,,,lol
Another thought comes to mind,
Do you have enough available power in that part of your house?
If a window box ac pops the breaker???