Audi b6 guy

Well lads im new to all this but iv had my 2004 1.9 tdi 130 bhp a4 b6 for years now and the miles are clocking up on her plus theres just not enough power and pull in the car it done me for years but i need to change my engine soon and dont want to go back to a 1.9 tdi so what are my options and how big can i go with an audi diesel engine without changing a huge amount in the engine bay and without spending silly money.. please give me options guys the more hp the better..thanks