Hi and welcome to the forum 🍻
Have you thought about the Hyper VSe basicaly an updated electric version of the Hyper 7 my son and i both run these and they go really well we have the 4s/100A version
https://www.modelsport.co.uk/hobao-hyper-vs-1-8-rtr-brushless-buggy-red/rc-car-products/396615
you will need to factor in batteries and possibly a charger depending on what you already have
to convert your Hyper 7 to an ST you'd prob be cheaper just buying an RTR ST
https://www.modelsport.co.uk/hobao-hyper-st-truggy-rtr/rc-car-products/26445