I hear you about the turf burn. I got the Adidas Tierros for that reason about a couple of months ago. They are very breathable and the padding isn't thick (which I like).
The fit and construction are both pretty good. They tend to run large, so see if you can try them on first if considering these.
As other said shorts+knee pads or look into 3/4 goalkeeper pants like https://www.amazon.com/dp/B00CJMECUG/ref=cm_sw_r_cp_apa_glt_fabc_3HYQS00KX55JVA11SZTS