QR would be my 1st choice. Then EY, CX and JL.
BA offers First Class in name only. It's really more like J+ and not even close to the quality of the other 3 OW options.
Our MH First experience was excellent but with all the issues surrounding MH these days, I'd probably avoid.
There is also QF on LHR-DXB where you could connect to QR or EY.