Suitable affordable speakers for Cary Cad 805AE

Hi Dear Fellows!!I bought a pair of second hand Cary Cad 805 AE monoblocks amplifiers.I consider myself lucky because this is not the sort of stuff you usually get for cheap money.The issue is that as I have not enought money to buy the wonderfull Tannoy westminster Royale or at least a Prestige series, I came accros to a pair of Thiel cs 1.5 speakers, and knowing that they had wonderful reviews and were affordable, I bought them.They sound very controlled, wright in timber and soundstage.Everything ok till here.The issue that bothers me a lot is that , as they are 4ohms, 3nominal, and 86db; after hearing a 5 or 6 hours in a weekend the power and output transformers of the cary amps get really hot.I'm very worried if these low sensivity and low impedance speakers could damage my power amps.Cary cad have the 4ohms binding posts, but I red that speakers of 8ohms and 90db sensivity will make the job easier for cary cad amps.
Has anyone used theese amps with thiels or other speakers of 4ohms?
Should I changed my speakers for the health of my amps?
If so,  could you recommend me a suitable speaker in the range of 2k-3k dollars to match theese marvellous amps?

Any experiences and suggestions will be highly appreciated!!!

Many thanks in advance!!

Cheers!

Raf