Playing 170 if you never run out of energy is not going to benefit you. Try and up your streaming bpm by 10 or so. Try playing high bpm bursts even if you're fingerlocking on them. I've been doing this for a long time and i still fingerlock sometimes but i've made massive strides in improvement, and improving at bursts made me better at streaming (e.g. bursting 240 made me better at streaming 190). Then again this is all coming from personal experience so it might not work the same way for you or anyone else.
As for finding stream/burst maps i personally found more as i played more but i can give you some examples of what i play:
Pretty much any Feint songs (like 161914 and Face Down)
Everything will freeze (https://osu.ppy.sh/beatmapsets/158023#osu/552068 and
https://osu.ppy.sh/beatmapsets/336471#osu/744672)
Dark Flight Dreamer (any mapset, but
https://osu.ppy.sh/beatmapsets/334469#osu/743818 is pretty good)
https://osu.ppy.sh/beatmapsets/114987#osu/297411
and so on. You can just go google for speed maps if you need more. You'll find some osu! forum threads in the first page of results