If by "modern" you mean LED lights you basically have two routes to follow with their assorted options. You can purchase LEDs with various FAA part approvals like Whelen or AeroLED for the replacement route, or you can purchase LEDs like Aero-Lites without the approvals for the alteration route but will require the assistance of an A&P. However, keep in mind when you get into the off-brand and cheaper side of the scale some of these LEDs can generate "noise" back into your electrical system. As to what brand is the best that is mostly subjective to the buyer and the depth of his pocketbook.