What sizes are you after, can’t really offer advice unless you state ya front and rear sizes mate
I wouldn’t start mixing tyres if your front still has life in it.
IMO a proffessionally plugged tyre will last till you’d change it due to wear so don’t go throwing money away unless it is towards the end of its life. I’ve done tackdays on plugged tyres and had a tyre with less than 100miles on it need plugging which I have carried on riding for over 1500 miles till it was worn out and it never lost air.
If you want a different profile rear you really need to put a matching front on as well. You will that way be able to appreciate the extra grip etc from how the tyre manufacturers designed them.
I love the Maxxis Supermax Sports, but there are apparently 2 versions, the old one I have not tried but is reported to be total cack, the new version however is my favorite tyre of all time so far and a pair of them for my GSX-R 750 is around £80 cheaper than my second best tyre; the Michilin Pilot Power 2CT, it also lasts twice as long, offers as good grip in the dry and despite the minimul tread pattern is awsome in the wet (I had knee down on wet roads the day I got them fitted) Trouble with the Maxxis is they are not supplying them in all sizes as yet.