Bike for my Dad - Stuck between 2

Afternoon all,

My dad is looking for a bike to try and get back into some sort of shape (little tubby at the mo).

He only wants to use it on canals and the odd bridleway so his requirements are pretty basic.

His budget is circa £300 and he has left it to me to point out some that fit the bill.

So far we have the Carerra Centos from Halfords
http://www.halfords.com/webapp/wcs/stor ... 65499#tab2

Or the Rockrider 5.3 from Decathlon
http://www.decathlon.co.uk/rockrider-53 ... 06682.html

If it was your money, which one would you get? I'm not too clued up on the lower end of the market spec and have no idea.

Alternatively, anything else that could be recommended for around the same price?

Cheers!