There are a number of N-reg planes around for rental. The best known are the Cirruses - there are several businesses doing this.
Perfectly legal. The restrictions are centred around the ANO Article 140 stuff (aerial work needing DfT permission) which basically affects the pilot renter receiving training in them, where the instructor gets paid. This may or may not affect the particular pilot, who may have to do his BFR (for example) in some G-reg.