choosing an undersink filter

[iwmtv]

my sister had a counter top amway filter system that attached to the faucet via two tubes. i am looking for an under sink one without the clutter. the water in my place runs a little brown initially if the water hasn't been used for a day or two. i'm guessing i need a sediment filter as well?

which one would have a good flow, the amway was a tad weak.

i also have a washing machine connected to the same kitchen sink. will this cause complications (too many splits off the cold water valve for example)?

is it best to connect the water filter near the top of the cold water connector (nearing the kitchen faucet)?

i was looking at the pentek systems for example. thank you!