37Kg too heavy?

Hi, Just bought "Iris," a 2010 CC19. Beautiful boat and great potential for fun. she's laying in Poole harbour at this time.
Can anyone comment on engines please.
I want electric start and the only small one I can find is a Tohatsu 6hp (MFS6Z SS) which weighs 37Kg. Is that too heavy? Further complication is for only £0.20 more (yes 20p) I can get the 8hp at exactly the same weight and shaft length; ie the same chassis, the carburettor just opens wider.
Any comments neg or pos appreciated.
Thanks
Nick Mair
Can anyone comment on engines please.
I want electric start and the only small one I can find is a Tohatsu 6hp (MFS6Z SS) which weighs 37Kg. Is that too heavy? Further complication is for only £0.20 more (yes 20p) I can get the 8hp at exactly the same weight and shaft length; ie the same chassis, the carburettor just opens wider.
Any comments neg or pos appreciated.
Thanks
Nick Mair