The only thing that's bugging me is the screen ratio which is 16:10 for most monitors.so i need an answer from someone who uses his ps3 with a 30 inch lcd
You're right, 30 inch monitors have an aspect ratio of 16:10. With the PS3 and PS4, you'll end up with black bars and the top and bottom of the screen (of the monitor supports a 1:1 mode) or the monitor will stretch the picture across the screen and you'll lose some of the image from the corners due to overscan.
There are two possible solutions:
1. Get a 27-inch monitor. In that regard, I would recommend either of the Samsung S27B750V, the HP 27XI, the LG 27EA63V, and the Asus VS278Q.
2. If screen size is important, get a 1080p 32-inch TV. It'll cost more than a 30-inch monitor, but since it natively supports a 16:9 aspect ratio, you won't encounter black bars or overscan. Both Sony and Samsung offer a lineup of 32-inch TVs that have great picture quality and features.