GXWH35F filter installation

[bimfi]

Last year I purchased a household water filter (GE smart water GXWH35F) but did not get around to installing it. The reason was that my house has PEX water tubing, and to be honest, it scared me a bit because I was told that one needed special tools for it.
Well, I finally decided that my water tastes horrid enough that I should at least attempt to install it.
Here is what I have. In my garage is my main water shut-off for the house. The PEX tubing (blue) protrudes out from the drywall about 4” to 5”, and then right angles to a shut-off ball valve and then right angles back into the wall. The distance between the two tubes is about 10.75” total.
What I want to do is install the filter housing between the two protruding tubes. My problem is that the distance between the inlet and outlet on the housing is 7 ", giving me only about ~1.5" per side to place any fittings.

My biggest concern is with the fitting that is supposed to go into the filter inlet and outlet. They are 1” threaded female openings. I have searched Lowes and Home Depot trying to find the right fitting combinations, but every one just increases the length. Any suggestions on the easiest way to install this filter, or where to go for more pipe fittings?