Get the one with the whitening mode and don’t spend a penny more unless you want the USB charing which IMO is not really worth it as the battery lasts so long on them.
I’ve got the one with the UV steriliser charger which tbh I think it a gimmic but it was cheap on offer from Amazon at Xmas. I tried the top of the range Colgate one and sent it back as it was horrible. Never been a fan of the Oral B type but most dentists seem to rate them. I keep going back to Sonicare and the heads are reasonable from Costco.
My last one broke just after 2 years which was annoying. Failure caused by mould eating through the flexible silicone seal at the top. The new ones have an updated design.
Ps technique with the sonicare is just gentle move it round your teeth with light pressure. No ‘brushing’ and don’t press hard.