If you’re tempted to simplify your transmission you can just take off your front mech and its control cable and see how you get on before splashing the cash. If you want to optimise your ratios that probably means a new wider range rear cassette. Really big sprockets will need a longer cage rear mech to take up the chain slack and some mechs will need an extended gear mech mount such as a ‘Goat Link’. If you choose a dedicated single-ring rear mech with a ‘clutch’ that will increase chain security and reduce noise over rougher surfaces and avoid the need for an extension mount. A narrow/wide chainring (somewhere between 38-44t depending on your rear block) will also increase chain security, smoothness and wear life of the whole system.