crikey where did you find those figures?! best i could find was 190bhp!
Claimed figures are not always accurate - rather they are most often bollocks.
190 seems more doable, though I would speak to a reputable garage to get an honest opinion (Steve at Stattller Porchse in Sheffield has sorted a few remaps for me in the past, he's a good guy and knows his stuff). He will also be able to tell you what's a safe raise in power in relation to engine stregnths/weaknesses.
Remaps are indeed very good. Figure out what you want it for, max speed, ultimate fuel efficiency etc and get an appropriate map to suit (they all have different characteristics).
Good luck!