Over Gunned???????

Hi All
I am in the process of buying a Wagner airless spray gun and am looking at the W400SE model which has a flow rate of 350ml/minand I can buy for $275 or the next model down, the W180P for $133,flow rate of 270ml/min.
The W400SE has 4 variable nozzle settings and has all I want but will I be overgunned as all I want to do is spray the inside of my t/g wooden house.
I think the W180P will do the job that I want but I seek your help in what I require. I will be spraying mainly acrylics with enamel for the doors.
Thanks in advance,
Bill