Integra Type R
Only get one that has had very regular oil changes and has been re-bushed
Edit, didn't see the baby part, probably a bad idea with two doors
IMO, the Mk1 Octy is looking a bit too dated these days, especially from the front. What about the LCR? IIRC that would give a slightly increased power output on an otherwise very similar car? The boot would also be easily big enough for a buggy.£5k would get you a very nice mk1 Octavia vRS. That said it will also buy you a decent ST220. For me the choice would come down to fuel economy.
If you want to be the right side of 30MPG day to day then get the Octavia, if you are happy dropping into the twenties then IMHO the ST220 is the better car.
The only thing I would suggest if the OP does go down the ST220 route is to go for a hatchback rather than the saloon posted above.