Drop Vulkan. He will too many points at this level.
OK you want to do rhinos. Then how about starting with
Vulkan 190
melta, combimelta,
ML, rhino 220
melta, combimelta,
ML, rhino 220
2 heavy flamer, 3 combimeltas rhino.(5 sternguard) 225
That is 4 scoring units, with rhinos in enough rhinos to work.
Then let's take 2 Land Speeder, heavy flamer, multi-melta = 70 because they are fun and we love Vulkan.
Then maybe your 2TLAC dread for some long range support and just in case we combat squad.
There would be where I would take your list, with maybe 20 pts spare.
Good luck