Online custom kite building material suppliers often carry Tyvek 1443R. The 1443R Tyvek is water repellant, breathable, softer & much more flexable than Tyvek Housewrap. However, the softer side of the 1443R is not nearly as durable as Housewrap. The fibers tend to lift when abraided. Something I like about the 1443R is its ability to absorb & hold polyurethane coatings, such as those sold to renew old tent floors that have lost some or all of their coating. PolyCoat, by Aquaseal, is a brand that I have used sucsessfully. If you lightly paint the 1443R with the polyurethane it becomes much more durable & waterproof. After lightly coating, the 1443R weighs appox 1.4 oz per sq yard. You can coat the 1443R before or after assembly. I have used this material to make bivy bags that are waterproof on the bottom, ends & sides when coated, yet breathable & water repellant on top. I have also coated the light weight disposable 1443R overbooties, sold for industrial use. These make very light winter mukluks for around camp. So far the coating has lasted thru 6 years or so of occasional use.
I would suggest that if you glue 1443R seams, do hard side to hard side. The softer side will delaminate easily when bonded. If you sew the 1443R, use a long stich length, appox 8 per inch, & do not back stich at the ends of seams, but rather glue seam ends with something like Fray Check. Tyvek is prone to tearing when stiching over perferates the material. You can use the PolyCoat as a seam sealer if your project is sewn.
One of many kite supplies "Kite Studio" link:
One brand of polyurethane coating "PolyCoat" link:
"Dritz Fray Check" link: