To be blunt, if you're looking to replace the vulture, don't. If you're just looking to expand your fleet, have different options and try other ships, then you're in the great position of not needing to sell your current ship to do it. The vulture is a definitive fighter.
Only replace it if you don't find it fun. I own a vulture, an fdl and a python, all set up for combat. The vulture is my favourite, the python second. I love the speed of the fdl but I dislike the placement of the huge hard point. The python is a pure gun boat and is the ship I love to use to run missions due to its versatility.
But the vulture is a beast in the field. If you haven't already fully upgraded it, I'd do that first. Then save up for another ship to complement your fleet, rather than retire the vulture.